Chesapeake Bay, Potomac River

Book 3 · Chapter 12

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Chesapeake Bay, Potomac River

Contents

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This chapter describes the Potomac River and the numerous tributaries that empty into it; included are Coan, St. Marys, Yeocomico, Wicomico and Anacostia Rivers. Also described are the ports of Washington, DC, and Alexandria and several smaller ports and landings on these waterways.

 COLREGS Demarcation Lines

The lines established for Chesapeake Bay are described in 33 CFR 80.510, chapter 2.

 Potomac River

flows into the west side of Chesapeake Bay 68.4 miles above the Virginia Capes. The west bank of the river, generally, is the boundary between Virginia on the west and Maryland on the east, and at the head of tidewater on the east bank is the city of Washington, D.C., the nation’s capital.

Hains Point at the junction of Anacostia River and the Washington and Georgetown Channels is 94.6 miles above the mouth of the Potomac. The head of tidewater navigation is at Chain Bridge, Washington, 101 miles above the mouth. The widest point of the river, 6.4 miles, is 11 miles above its mouth.

Mileages on Potomac River in this chapter, such as Mile 13E, Mile 41W, and Mile 51N, are the nautical miles above the midchannel entrance point, which is 4.8 miles northwest of Smith Point on a line between Smith Point and Point Lookout; that point is 68.4 miles above the Capes. The letters N, S, E or W following the mileage numbers denote by compass points the side of the river where each feature is located.

It is to be understood that the mileages given are approximations. The intended degree of accuracy is only supposed to be enough to put the user of the chart in the general vicinity of the cited object, for the purpose of locating the object.

Traffic on the river consists chiefly of petroleum products; sand, gravel and crushed rock and some newsprint and fertilizers. Drafts of vessels navigating the river usually do not exceed 20 feet.

 Channels

The Federal project depth is 24 feet for Potomac River from the mouth to Hains Point. Channel depths of 38 feet or more are available to Ragged Point, 20 miles above the mouth; thence the controlling depth through the dredged cuts is about 18 feet to Hains Point. The channels are maintained at or near project depths. For detailed channel information and minimum depths as reported by the U.S. Army Corps of Engineers (USACE), use NOAA Electronic Navigational Charts. Surveys and channel condition reports are available through a USACE hydrographic survey website listed in Appendix A.

 Anchorages

Vessels bound up or down the river anchor anywhere near the channel where the bottom is soft; vessels sometimes anchor in Cornfield Harbor or St. Marys River. Above Alexandria, vessels usually go to the wharves; there is little or no anchorage for anything but small craft. Near the mouth of the river, small craft can find secure anchorage in most of the tributaries; Smith Creek is said to have best protection from all winds.

Fishtrap areas extend upriver from the mouth to St. Clements Island. Limits of the areas are shown on the chart. Mariners are warned that numerous uncharted duck blinds and fishing structures, some submerged, may exist in the fishtrap areas; such structures are not charted unless known to be permanent.

Numerous markers, established and maintained by the Potomac River Fisheries Commission, mark the Maryland and Virginia jurisdictional fishing boundaries on both sides of the Potomac River from Chesapeake Bay to Mattawoman Creek at Mile 71.5E in Maryland and Occoquan Bay at Mile 73.8W in Virginia and at the entrances to many of the bays and rivers.

The markers are pile structures with white square daymarks with orange borders and identifying black letters “PRM,”“PRV” and numbers.

 Danger zones and restricted area

The Potomac River and its tributaries are used extensively by the military establishments for testing operations and gunnery practice. (Limits and regulations for these areas are given in 33 CFR 334.230, 334.240 and 334.250, chapter 2.)

 Tides

Above Washington, the river is tidal as far as Chain Bridge. The tides are influenced by the force and direction of the wind and by freshet conditions and may at times vary considerably. Daily predictions for Washington, DC, are available from the Tide prediction service at tidesandcurrents.noaa.gov. Links to a user guide for this service can be found in chapter 1 of this book.

 Current

The current in Chesapeake Bay off the mouth of Potomac River can be hazardous to smaller vessels and pleasure boats at ebb tide, when wind and current are opposed and with northwest winds. These conditions are more pronounced off Smith Point. The currents in the Potomac River follow the general direction of the channel. The velocities vary throughout the river and are influenced by wind and freshets. There may be little or no flood current during freshets.

The current velocity is weak in the lower part of the river between the entrance and Piney Point, averaging less than 1.0 knot. See the Tidal Current prediction service at tidesandcurrents.noaa.gov for specific information about times, directions, and velocities of the current at numerous locations throughout the area. Links to a user guide for this service can be found in chapter 1 of this book.

 Ice

During severe winters the tributaries of the Potomac are closed by ice and the river is frozen over to Cedar Point; the upper part is then closed to navigation. During ordinary winters the powered vessels plying the river keep the channel open.

When threatened by icing conditions, certain lighted buoys may be replaced by lighted ice buoys with reduced candlepower or by unlighted buoys, and certain unlighted buoys may be discontinued.

 Freshets

Freshets occur at irregular intervals but usually do not interfere with navigation below Alexandria unless accompanied by floating ice.

 Pilotage, Potomac River

Pilotage is compulsory on the Potomac River for foreign vessels and U.S. vessels under register in the foreign trade. Pilotage is optional for U.S. vessels in the coastwise trade who have on board a pilot licensed by the Federal Government for these waters.

The Association of Maryland Pilots offers pilotage to any vessel bound for a port on the Potomac River. (See Pilotage, chapters 3 and 9.)

 Smith Point to Piney Point

is entered between Smith Point and Point Lookout; the width of the entrance, normal to the channel, is about 5 miles.

The fishtrap areas in the lower river are shown on the charts.

 Danger zones

Danger zones for military testing operations extend from the mouth of the river to about 4 miles above the Potomac River Bridge, Mile 43.4. (See 33 CFR 334.230, chapter 2, for limits and regulations.) When military firing operations are in progress in the danger zones, range patrol boats with white hulls and international orange superstructures and shoreline spotters are stationed near the firing areas. The range patrol boats display a square red flag during daylight hours and an all-round red light from the mast at night. Surface traffic on the range is controlled by the range patrol boats and the shoreline spotters on VHF-FM channel 16.

, the southerly entrance point, is low and inconspicuous. A shoal area that extends eastward from the point has depths as little as 8 feet 2 miles from shore; a buoy marks the northeast edge of the shoal.

Smith Point Light (), 52 feet above the water, is shown from a white square brick tower and octagonal dwelling on a brown cylindrical pier about 2.5 miles east-southeast of the point.

, used by local fishermen and pleasure craft, empties into the Potomac River and Chesapeake Bay at Smith Point. The approach to the river is marked by a light. A marked dredged channel leads from the Potomac River and Chesapeake Bay junction through a jettied entrance to a marked natural channel in the river. Lights mark the outer ends of the jetties. The entrance is subject to shoaling due to the strong current between the jetties; mariners are advised to exercise caution. Daybeacons mark the upper reaches of the river to a point about 3 miles above the entrance; a depth of about 6 feet can be carried for 4 miles upriver with local knowledge.

, marked by daybeacons, empties into the south side of Little Wicomico River about 0.6 mile above the entrance. A small-craft facility on the east side of the creek can provide gasoline, diesel fuel, water, ice, berths with electricity, a pump-out station, a launching ramp, wet and dry storage and marine supplies. The reported approach depth was 4.5 feet in 2010. Hull, engine and electronic repairs can be made; lift to 12 tons.

 Cable Ferry

A cable ferry crosses Little Wicomico River at , 1.5 miles above the entrance. The ferry carries passengers and vehicles. The ferry operates between the hours of 0700 and 1900, Monday through Saturday, and 0700 to dark during the winter months. When the ferry is underway, the unmarked cable is suspended about 3 feet above the water surface and is dropped to the bottom when not underway. DO NOT ATTEMPT TO PASS A MOVING CABLE FERRY.

 Small-craft facility

A small-craft facility on the north side of the river about 3.6 miles above the entrance has berths with electricity. Gasoline, diesel fuel, water, ice, some marine supplies, a pump-out station, a launching ramp and wet and dry storage are available. In 2010, 6 feet was reported in the approach. A marine railway at the facility can handle craft up to 80 feet for hull, electronic and engine repairs; lift to 25 tons.

, the northerly entrance point of Potomac River, is low but well marked by a 195-foot lighted communications tower and several buildings. The shoal that extends about 1 mile southward from the point is marked by Point Lookout Light (), 39 feet above the water, shown from a skeleton tower with a black and white diamond-shaped daymark on a pile structure and marked “DANGER”.

, just inside Point Lookout, is sheltered from northerly and northeasterly winds; vessels bound up and down the bay frequently use it as an anchorage for the night. The shoaling is gradual, except off and at the south end of the shoal that extends southward from Point Lookout; at these places the hard sand bottom drops off abruptly. An 18-foot spot, and rocks covered 16 and 17 feet, are about 0.7 mile westward from Point Lookout, and a 10-foot spot lies between them and the Point Lookout shore.

is 0.8 mile north-northwest of Point Lookout. The lake is entered from Cornfield Harbor through a private channel marked by a light and daybeacons; in 1976, the reported controlling depths were 8 feet in the entrance and 6 feet in the basin and alongside the piers. The east side of the lake is the site of . The state boating facility on the east shore of the lake has gasoline, water, ice, limited marine supplies and a sewage pump-out station. No overnight berthing is permitted; anchorage in the basin is allowed in an emergency.

(), Mile 7.8S, has depths of 13 to 7 feet for 4.5 miles to within 0.5 mile of the head. The river is used mostly by local oyster and fish boats. A 500-yard lane in the approach is kept clear of fishtraps; the initial course through the lane is 230°. The entrance to Coan River is marked by buoys and lights and is easy to navigate; the channel inside is marked at the critical points by daybeacons and bush stakes. A warning daybeacon at about , marks a shoal area that reduces the channel width to about 30 feet. Shoaling to an unknown extent was reported in the channel about 200 yards eastward of Daybeacon 10 and about 200 yards eastward of the small point about midway between Daybeacons 14 and 16.

, on the north side of Coan River 0.6 mile above the mouth, has depths of 8 feet for most of its 1-mile length. A shoal extends halfway across the entrance from the point on the west side. Gasoline, diesel fuel, water, ice, berths, pump-out station, launching ramp, wet and dry storage and marine supplies are available at the small-craft facilities on the east side of the creek at . In 2010, 8 feet was reported alongside. Hull, engine and electronic repairs can be made; lift to 25 tons.

, on the west side of Coan River 0.7 mile above the mouth, has depths of 9 to 13 feet to the forks 1.5 miles above the entrance. The channel in The Glebe is clear except for a shoal that extends well off from the point on the south side 0.6 mile above the entrance.

is on the west side of Coan River 1 mile above the mouth. The boatyard on the south side makes hull, engine and electronic repairs; lift capacity, 25 tons. Gasoline, diesel fuel, ice, water, berthing with electricity, a pumpout station, some supplies, a launching ramp and wet and dry storage are available. In 2010, 10 feet was reported alongside.

The grain wharf at , on the west side of Coan River 3.4 miles above the mouth, has depths of 9 feet at the outer end. wharf, directly across the river from Bundick, is in ruins. The overhead power cable from Coan to Bundick has a clearance of 60 feet.

, Mile 8.5N, is used by many small fishing and pleasure boats and has the best protection along this part of the river from all winds. A depth of about 8 feet is available over the bar to the junction of the two main branches, 1.5 miles above the entrance light. The entrance is well marked. The lane through the fishtraps can be navigated on a course of 355°.

, on the east side of the entrance to Smith Creek, has fish wharves with depths of 5 to 10 feet at their outer ends. Small-craft facilities on the east side of the creek, just above the entrance, can provide gasoline, diesel fuel, water, ice, berths and marine supplies. Hull and engine repairs can be made. Largest haul-out capacities; marine railway, 200 feet; lift, 35 tons.

St. Marys River, Mile 9.7N, is 2 miles wide at the entrance and about 600 yards wide at St. Marys City, 5.5 miles up. The channel has depths of 20 feet or more to St. Marys City, then shoals gradually to 12 feet at and to 8 feet at , 8 miles above the mouth. St. Marys River is sometimes used as an anchorage by the deeper draft vessels seeking shelter from heavy gales, but small boats prefer Smith Creek. The river has very little traffic other than local fishing craft. The course through the fishtraps off the entrance is 345°.

St. George Island, on the west side of the entrance to St. Marys River, is long, low and sparsely wooded. The island is thickly settled, mostly by oystermen and fishermen, and is used to some extent as a summer resort. St. George Bar extends 1.3 miles southeastward from the island; a lighted buoy is about 1 mile southeastward of the outer end of the bar.

, on the southeast end of St. George Island, is entered by a marked dredged channel that leads to fishing piers and a turning basin inside.

St. George Creek, which joins St. Marys River along the northeast side of St. George Island, has a narrow, crooked channel with depths of about 9 feet for 3.5 miles; the channel is marked for about 2.8 miles. The creek is used extensively by oystering and fishing boats and by pleasure craft.

A marked channel enters St. George Creek at the fixed bridge on the north side of St George Island. The bridge has a width of 35 feet and a vertical clearance of 17 feet. Overhead power cables on both sides of the bridge have a clearance of 29 feet.

The town of , on the west side of St. George Creek 2.5 miles above the mouth, has several private wharves with depths of 5 to 8 feet.

At , on the west side of St. George Creek 3.5 miles above the mouth, is a boatyard where hull repairs can be made; marine railway, 40 feet. Gasoline, water and berths are available.

enters the west side of St. Marys River about 3 miles above the mouth. The creek, marked by daybeacons and a light, is used chiefly by pleasure craft. A marina at , on the east shore of the creek about 1.1 miles above the mouth can provide berthing with electricity, gasoline, diesel fuel, ice, water, a pump-out station, wet and dry storage and marine supplies. In 2010, the reported alongside depth was 6 feet. Hull, electronic and engine repairs can be made; lift capacity, 75 tons.

St. Inigoes Creek enters the east side of St. Marys River about 3.5 miles above the mouth. Depths of 11 feet can be carried to the junction of St. Inigoes Creek and , 1.3 miles above the mouth. The creek is unmarked.

is on the east side of the creek, 0.6 mile above the mouth. St. Inigoes Coast Guard Station is on the west side of its entrance.

St. Marys City, at , on the east side of St. Marys River 5.5 miles above the mouth, was the original capital of Maryland. Few traces of the original town remain, but the statehouse was reconstructed in 1934 from the ruins of several other buildings nearby. A landing on the south side of the point has a depth of about 9 feet at the outer end.

, Mile 10.2S, has depths of 19 to 12 feet to the forks 1.4 miles above the entrance. Lights mark the channel to the forks and bush stakes mark the edges of the tributary channels. The initial course through the fish stakes off the entrance is 244°.

There are small-craft facilities on the north fork of Yeocomico River, and on the south side of White Point Creek, the westerly arm of Shannon Branch. Gasoline, diesel fuel, water, ice, berthing with electricity, some marine supplies and a pump-out station are available. Hull, engine and electronic repairs can be made. In 2010, a depth of 8 feet in the approach and alongside was reported. A 65-foot marine railway and lift to 50 tons are available in White Point Creek.

, the west fork, has depths of 13 to 7 feet to Kinsale, on the southwest side 1.7 miles above the entrance. The fixed highway bridge at Kinsale has a width of 29 feet and a clearance of 8 feet. The bulkhead wharf has depths of 10 feet alongside; the grain elevators on the wharf are prominent. Small-craft facilities are on the north side of the river and at Kinsale. Gasoline, diesel fuel, berthing with electricity, pump-out, water, ice, marine supplies, wet storage and a launching ramp are available.

, the south fork, has depths of 13 to 7 feet to , on the west side of 2 miles above the entrance of the south branch. An overhead power cable with a clearance of 50 feet crosses Lodge Creek about 2.4 miles above the entrance. The fish wharf at , on the west side of the entrance, has depths of 6 feet at the wharf. Several small landings on the south side of the point have depths of 9 feet at their outer ends.

is on the west side of South Yeocomico River 1 mile south of the entrance. The marine railways at the settlement can handle vessels up to 80 feet. The north landing at the cannery has depths of 9 feet alongside, and the south landing has depths of 5 feet. The lumber-mill landing 0.2 mile southwestward has depths of 7 feet alongside.

 Small-craft facilities

Small-craft facilities are on the south side of Harryhogan Point and on the east side of Lodge Creek. Gasoline, diesel fuel, berths, electricity, water, ice, pump-out station, storage, launching ramp and marine supplies are available. Hull and engine repairs can be made. The largest marine railway in the area can handle craft up to 80 feet; a 50-ton lift is available.

() is at Mile 15.9N. An abandoned lighthouse tower and a former Coast Guard station are on the point. The former Coast Guard wharf and the small private landings east of Piney Point have depths of about 5 feet at their outer ends. Gasoline and some supplies are available at a dock about 1 mile northeast of the point.

A prominent T-head pier of an oil company extends 1,000 feet southwestward from Piney Point. The pier, marked by private lights, has depths of about 35 feet along its 684-foot outer face. The pier is owned and operated by L. P. Steuart Co.

Immigration, quarantine and customs officials come from Baltimore upon notification by the maritime exchange that tankers are due at Piney Point; vessels are boarded at the pier.

 Bonum Creek to Colonial Beach

Limits of the fishtrap areas that extend upriver as far as St. Clements Island are shown on the charts.

 Danger zones

Danger zones for military testing operations extend upriver to about 4 miles above the Harry W. Nice/Thomas "Mac" Middleton Bridge (U.S. Route 301), Mile 50. (See 33 CFR 334.230, chapter 2, for limits and regulations.)

(), Mile 16.0S, is entered from the Potomac River by a dredged channel that leads through jetties to an anchorage basin 0.4 mile inside. A light and daybeacons mark the channel to the basin. The creek is used chiefly by fishing craft.

, Mile 18.7E, is entered by a marked dredged channel protected on both sides of the entrance by jetties; lights mark the outer ends of the jetties. A marina on the south side of the entrance has gasoline, diesel fuel, berths, electricity, water, ice, launching ramp, storage and some marine supplies. Hull and engine repairs can be made with a 30-ton lift. A fish pier with 6 feet at the outer end is just east of the marina fuel pier. Another marina is on the south side of the creek 1.2 miles above the entrance; depths of 5 feet are reported alongside the piers. Gasoline, berths, electricity, water, ice, pump-out station, storage, launching ramp and limited supplies are available. Hull, engine and electronic repairs can be made with a 25-ton lift.

A shoal extends 0.5 mile offshore from , at Mile 19.1S. A light is near the outer edge of the shoal. A marina, south of Ragged Point, can provide gasoline, diesel fuel, berths with electricity, water, ice, a pumpout station, a launching ramp, dry and wet storage and limited marine supplies. In 2009, 7 feet alongside was reported. Hull, engine and electronic repairs are available; lift capacity, 30 tons.

, Mile 21.7S, has depths of 15 to 11 feet for 2 miles, thence the depths decrease to 4 feet at a point 4 miles above the entrance. The critical points are marked as far as the narrows 2.2 miles from the entrance; the shoals are usually bush-staked.

, on the east side of Lower Machodoc Creek 1 mile above the entrance, is entered by a marked dredged channel that leads to a boat basin inside. , the village along the north shore of the cove, has piers with depths of about 6 feet at the outer ends. A large oyster-packing plant is on the north side of the entrance to the cove. Small-craft facilities in the cove can provide gasoline, diesel fuel, water, ice, berths and marine supplies. Hull and engine repairs can be made.

, Mile 25S, has depths of 20 to 15 feet in the middle, and is the approach to Nomini Creek and Currioman Bay. The shoaling is abrupt on the east side of the bay and gradual on the west side.

is entered through a dredged channel that extends about 1.2 miles above the entrance to Hickory Point. The channel is well marked by lights and daybeacons. There is a long jetty on the east side of the entrance to the creek. Traffic on the creek consists chiefly of seafood and fertilizer.

Mariners should be alert for unmarked fishtrap structures in Nomini Creek.

The highway bridge at Nomini, about 3.5 miles above the entrance, has a 45-foot fixed span with a clearance of 18 feet. The fixed highway bridge at Prospect Hill, 5 miles above the entrance, has a 30-foot span with a clearance of 10 feet.

is separated from the west side of Nomini Bay by , a narrow 2-mile-long spit that is wooded in the middle. Currioman Bay has depths of 7 to 10 feet in the entrance from the head of Nomini Bay and in most of the area back of Hollis Marsh; the entrance from Potomac River at the northwest end of Hollis Marsh has depths of only 2 to 3 feet.

, Mile 25.2N, is a favorite anchoring ground for yachts. Commercial traffic consists chiefly of petroleum products. Drafts using the bay are mostly 6 feet or less, but occasionally vessels drawing up to 11 feet come inside.

The bay has depths of 15 to 11 feet for 4.5 miles, thence about 5 feet to Leonardtown, 5 miles above the entrance.

A 1,000-yard lane extends through the fishtraps off the entrance to Breton Bay; the initial course through the lane is 352°. The shoal that extends eastward from Heron Island Bar to the Breton Bay approach is marked by an obstruction buoy, and another shoal that extends southwestward from , on the east side of the entrance, is marked by a light near its outer end. Daybeacons and lights mark the bay channel to within 0.5 mile of Leonardtown.

, on the north side and 1.6 miles above the mouth of Breton Bay, had a reported controlling depth of 5 feet along the middle of the creek in 1980. The narrow entrance is between shoal spits marked by daybeacons and stakes. Ice, water, a pump-out station, some marine supplies and berthing with electricity are available. The marine railways on the west side of the creek can handle boats up to 60 feet for hull and engine repairs; lift capacity, 20 tons.

A channel with a controlling depth of 6 feet, marked by piles, leads into the bight just southwestward of the entrance to Combs Creek. Gasoline, berths and some supplies can be obtained.

is on the east side of Breton Bay 3 miles above the mouth. A bar with depths of less than 1 foot extends 500 yards northwestward from the point and is marked at its outer end by a light.

is on the west side of Breton Bay 4.5 miles above the mouth. A daybeacon marks the outer end of a bar that extends off the point.

is on the north side of Breton Bay 5 miles above the mouth.

St. Clements Island is at Mile 27.0N. Near the south end of the thinly wooded island is a prominent cross that commemorates the first Catholic mass by English settlers in America on March 25, 1634. Shoals extend from the island in all directions. The long pier on the northeast side of the island has a depth of about 16 feet at the outer end; supply and fishing boats use the pier.

, about 1 mile eastward of St. Clements Island, is an extensive shoal area mostly covered at low water; the bar is marked at the eastern and western ends by buoys.

St. Clements Bay, north-northeastward of St. Clements Island, has three entrances. The eastern entrance, between Heron Island Bar and the mainland, is by the way of the Breton Bay lane through the fishtraps; this entrance has depths of 20 to 16 feet and is easily followed in the daytime. The middle entrance, between Heron Island Bar and St. Clements Island, has depths of 15 feet or more and is approached through a 500-yard lane in the fishtraps on an initial course of 352°; this entrance is narrow and crooked but is marked by a light and buoys and is easily followed in the daytime.

, the western entrance, leads from the Potomac River to St. Clements Bay between St. Clements Island and the mainland 0.5 mile to the north-northwestward; the controlling depth is 2 feet. In 1993, depths of 2 to 3 feet were reported 100 yards northeast of Daybeacon 7 in about Aids to navigation in Dukeharts Channel are placed for a passage from east to west.

St. Clements Bay has channel depths of 14 feet for 3 miles then shoals gradually to 8 feet 5 miles above the entrance. The mean range of tide is 1.8 feet.

St. Patrick Creek, on the west side of St. Clements Bay 0.5 mile above the mouth, is entered through a marked dredged channel. The creek is much frequented by fishermen, oystermen and pleasure craft. There are several small-craft facilities along the creek above , on the south side 0.4 mile above the entrance. The speed limit is 6 miles per hour in the creek.

is on the west side of St. Clements Bay about 1.5 miles above the mouth. The entrance to the creek has a depth of 11 feet, except for a shoal reported encroaching the channel from the north entrance point. The creek shoals gradually from 11 feet at the entrance to 3 feet near the head. The landings at , on the south side just above the entrance, have depths of 4 to 7 feet at the outer ends. A small-craft facility on Morris Point can provide gasoline.

St. Catherine Sound, Mile 29.0N, has depths of 5 to 9 feet behind St. Catherine Island. Two marked dredged channels lead into the sound; one at the northwesterly end and the other at the southeasterly end. Partially submerged pilings were reported in the sound near the southeasterly channel north and east of St. Catherine Island in about and The wharves along the shore of the sound are privately owned.

, on the north side of St. Catherine Sound, has depths of 4 feet in the entrance and 6 to 2 feet inside. A state pier on the west side just inside the entrance has depths of 4 feet at the outer end. The marine railway just upstream can handle boats up to 45 feet for hull and engine repairs.

() is at Mile 31.0N. Its commercial traffic consists chiefly of shellfish vessels. Drafts of vessels using the river are mostly 6 feet or less.

The river is characterized by long spits, with little depth and abrupt outer ends that extend to the edges of the channel in several places. The entrance is 1.3 miles wide between St. Margaret Island on the east and on the west. Cobb Point Bar, which extends 1 mile southeastward from the island, is marked at the outer end by a light; the shoal extending 0.6 mile westward from St. Margaret Island is marked by a daybeacon.

The Wicomico River channel has depths of 40 to 12 feet for 5 miles, thence 6 feet with local knowledge for 3 miles, and then decreasing to 3 feet to the head, 11 miles above the mouth. The channel is marked at the most critical points for about 8 miles.

An overhead power cable with a clearance of 38 feet crosses the river about 10 miles above the mouth. Three suspension towers in the river support the cable.

Neale Sound is on the west side of the entrance of Wicomico River between Cobb Island and the mainland and affords secure anchorage for small boats. An east cut entrance is also available from the Wicomico River. Both entrances are marked by lights, and the critical part of the channel at the northwest end is marked by daybeacons. A fixed highway bridge with a vertical clearance of 20 feet crosses Neale Sound.

Several small-craft facilities are on both sides of Neale Sound at the bridge.

is on the east side of Wicomico River 1.5 miles above the mouth. A state pier and a gasoline pier have alongside reported depths of 8 and 4 feet, respectively. Gasoline and some supplies are obtainable.

, on the west side of Wicomico River 3 miles above the mouth, is used by oyster boats as an anchorage.

From Nomini Bay to within 2 miles of Popes Creek () the Virginia shore of Potomac River is backed by high ground. Along this stretch are and the valleys between them.

, Mile 33.5S, leads to Wakefield and the .The controlling depth is about 1.5 feet in the entrance, and a stone jetty 2 feet high extends 200 feet offshore from the point on the north side. Current velocity up to 4.5 knots has been reported in the entrance.

, Mile 36.1S, has depths of 7 to 5 feet in a marked narrow channel for 2 miles to , then the depths decrease to 3 feet at the fixed concrete highway bridge, 4 miles above the entrance. A marina, on the south side of the creek, can provide gasoline, berths with electricity, water, ice, a pumpout station, a launching ramp, dry and wet storage, and some marine supplies. In 2010, a depth of 6 feet was reported in the approach and alongside. Hull, engine and electronic repairs are available; lift capacity, 40 tons.

, Mile 36.5S, is a summer resort just north of Mattox Creek. The largest of the piers on the river side of the town is the municipal 450-foot T-head pier 1.2 miles above the south end. The pier has reported depths of 6 feet at the outer end.

, back of Colonial Beach, is entered between , at the south end of the town, and , 150 yards westward. The creek is used extensively as an anchorage. The dredged channel, marked by lights and daybeacons, leads from the entrance of the creek to a basin at at Colonial Beach. The entrance is narrow and mariners are requested to transit at low speed to avoid wash damage to vessels moored in the creek.

There are numerous small-craft facilities along the east side of the creek below and above Robins Grove Point, and a yacht club is on the eastern side of the entrance to the creek.

 Potomac Beach to Morgantown

is at Mile 38.8W. A private pier is the only usable landing. In 1982, a reported depth of 2 feet was available to the landing.

, entered just westward of Potomac Beach, has depths of 2 feet in the entrance and 5 to 2 feet for 1 mile upstream. The creek has no wharves and is little used.

Upper Machodoc Creek is at Mile 40.2W. The Naval Surface Warfare Center is at Dahlgren, on the north side of the entrance to the creek, but also occupies land for a considerable distance along the south shore; the center monitors VHF-FM channel 16. (See 33 CFR 334.230, chapter 2, for the limits and regulations governing the danger zones.) River currents may have transported unexploded ordnance outside the charted danger zone limits; extreme caution is advised. The tanks and radio masts at Dahlgren are prominent.

Two well-marked, Navy-maintained channels lead from the Potomac River to the basin and wharves at Dahlgren. Above Dahlgren, only small piers are found along the banks of Upper Machodoc Creek. A fixed highway bridge with a 47-foot span and a clearance of 10 feet crosses the creek 3.7 miles above the entrance.

, on the north side of Upper Machodoc Creek 1 mile above the mouth, has depths of 4 to 2 feet to the highway bridge 1.1 miles above the entrance. An overhead power cable 0.6 mile above the entrance has a clearance of 28 feet.

A marina is on the north side of the entrance to Williams Creek. Gasoline, diesel fuel, berthing with electricity, a pump-out station, a launching ramp, wet and dry storage and marine supplies are available. In 2010, a depth of 6 feet alongside was reported. Hull, engine and electronic repairs can be made; lift capacity, 12 tons.

is at Mile 42.1E. A light is shown from a white skeleton tower on piles in depths of 3 feet on the west edge of the main channel 0.7 mile westward of the point.

is on the south side of Lower Cedar Point. There are strong cross currents south of the point. The landings that remain intact are suitable only for small boats.

 Harry W. Nice/Thomas "Mac" Middleton Bridge to Powells Creek

The Harry W. Nice/Thomas "Mac" Middleton Bridge (U.S. Route 301), Mile 50, has a fixed channel span with a clearance of 135 feet. The piers on either side of the channel span carry fog signals and are marked by fixed red lights. The channel centerline is marked by a fixed green light.

There is a small-boat basin and marina just above the Harry W. Nice/Thomas "Mac" Middleton Bridge on the Maryland side. The entrance channel and basin have depths of about 6 feet. Gasoline, diesel fuel, berths and marine supplies are available. Hull and engine repairs can be made; lift, 20 tons.

 Danger zone

A danger zone for military testing operations extends about 4 miles upriver from the Harry W. Nice/Thomas "Mac" Middleton Bridge. (See 33 CFR 334.230, chapter 2, for limits and regulations.) Unexploded ordnance may exist in the vicinity of Mathias Point Neck, Cedar Point Neck, Tayloe Neck and Nanjemoy Creek.

is at Mile 44.5W. A 3-foot shoal is 0.6 mile southeastward of the point on the west edge of the channel.

, Mile 45.4E, is not navigable. The village of Popes Creek, 0.2 mile northward, has overnight docking available at a crabhouse pier - seasonal, spring only. The former railroad wharf is in ruins.

Between Popes Creek and Upper Cedar Point, 4.5 miles upriver, the Maryland shore of Potomac River bends northward about 2 miles to form Port Tobacco River Flats, which have shoal spots of 3 to 5 feet but generally navigable depths of 7 to 10 feet. , at the head of the bight, has depths of 7 feet for 1.6 miles and thence 5 to 3 feet for another 1.3 miles. A light and daybeacons mark the channel.

, on the east side of Port Tobacco River 1.2 miles above the mouth, is a summer resort. , 4.4 miles above the entrance, is now the head of practical navigation. Marinas at the town have gasoline, berths and some supplies. Hull and engine repairs can be made; lift, 15 tons.

is at Mile 47.7S. A light is shown from a skeleton tower on piles in depths of 3 feet on the south edge of the main channel 0.3 mile northward of the point.

, at Mile 50.0N, is marked by a light shown from a skeleton tower on piles in depths of 3 feet on the north edge of the channel 0.5 mile southeastward of the point. Give the light a berth of at least 200 yards.

, Mile 51.0N, has a controlling depth of about 4 feet in a privately marked channel to a small-craft launching ramp about 4 miles above the entrance.

is at Mile 53.1S. A light, shown from a pile structure in depths of 1 foot 0.5 mile off the point, marks the shallowest part of a shoal area along the southeast edge of the channel.

Maryland Point Light (), Mile 55.8S, 42 feet above the water, is shown from a skeleton tower with a black and white diamond-shaped daymark on piles in depths of 9 feet on the south edge of the Potomac River channel 0.7 mile southeastward of . Other shoals east and west of the light are marked by buoys.

Two white dish-shaped antennas 1.4 miles northwest of Maryland Point are conspicuous.

Gasoline, ice, water, a pump-out station and limited berthing with electricity can be obtained at , Mile 57.4S. Depths to the pier are about 4 feet. Hull and engine repairs can be made; lift capacity, 25 tons.

, Mile 58.5S, is used only by small motorboats. Bull Bluff, on the south side of the entrance, is high and wooded. The creek has depths of 7 feet in the entrance, thence 3 feet for 2 miles. The best water favors the south side of the entrance. Gasoline and water are available at small-craft facilities on the south side of the creek 1 mile and 2 miles above the entrance. Hull and engine repairs can be made at the more easterly facility.

Aquia Creek, Mile 60.4W, has depths of 4 to 5 feet to the railroad bridge, and thence 2 feet to Coals Landing, 5 miles above the mouth. The entrance to the creek is marked by lights and daybeacons. A fixed railroad bridge, 3 miles above the entrance, has a width of 46 feet and a clearance of 26 feet. An overhead power cable just south of the bridge has a clearance of 36 feet. Small-craft facilities are on the south side of the creek close above and below the bridge.

, Mile 61.5E, is marked by a light. is on the point. The broken piling of a former landing 300 yards south of the light is nearly awash at high water.

There is danger of striking submerged hulks in the mile-wide former restricted anchorage area that extended 2.5 miles upriver along the Virginia shore from directly opposite Smith Point.

is at Mile 64.4E. is on the north side of Liverpool Point. There are several sunken vessels in the middle and north part of the bay. The western danger limit is a line from Liverpool Point to Sandy Point. A buoy marks the inner edge of the river channel off the bay. The Mallows Bay-Potomac River National Marine Sanctuary consists of an area of approximately 18 square miles of waters of the state of Maryland and the submerged lands thereunder, over, around, and under the underwater cultural resources in the Potomac River—see 15 CFR 922.1 through 922.50 and 922.200 through 922.206, chapter 2, for limits and regulations.

A restricted area has been established on the Potomac River around Chopawamsic Creek and Chopawamsic Island. (See 33 CFR 334.235, chapter 2, for limits and regulations.)

, Mile 67.7W, is a training site of the U.S. Marine Corps. The T-head pier has depths of 25 to 30 feet at the face, and the launch harbor immediately south of the pier has depths of about 10 feet. Except in emergencies, the pier and harbor are restricted to government vessels.

Quantico Creek, Mile 68.2W, has depths of 7 feet in a narrow, crooked entrance channel, and about 2 feet for 2 miles upstream. The fixed railroad bridges over the entrance have 30-foot spans with a clearance of 12 feet. An overhead power cable along the west side of the bridge, and another one 1.3 miles above the bridge, have clearances of 8 feet and 41 feet, respectively. A small landing on the south side of the entrance is used by local pleasure boats.

is at Mile 68.5W. A private light marks the powerplant wharf 0.2 mile northward of the point. An overhead power cable 0.8 mile above Possum Point has a clearance of 170 feet for a midwidth of 1,440 feet over the main channel and 124 to 70 feet elsewhere. The six support structures for the cable are marked by lights.

, Mile 69.2E, has depths of 5 feet in the entrance but shoals rapidly farther up. The creek is little used.

 Danger zone

A danger zone of a Navy explosion test area includes part of Chicamuxen Creek and extends northeastward in Potomac River up to 0.5 mile off the Maryland shore for about 5 miles to Indian Head. (See 33 CFR 334.240, chapter 2, for limits and regulations.)

An oil and asphalt terminal is at , Mile 70.3W.

The Government wharf at the north end of , Mile 70.6E, has depths of 15 feet at the outer end and is marked by a light. Lights also mark the ends of the breakwater on the north side. Landing is permitted only in case of emergency.

, Mile 71.5E, has easily navigated depths of 7 to 5 feet for 1 mile to the marsh that extends southeastward from to the edge of the channel. The channel is marked by a daybeacon and lights. Above this marsh, the creek channel has greater depths for 3 miles, but meanders back and forth between the flats and is almost impossible to follow without a guide. A pier and launching ramp for a public picnic facility is at , 2 miles inside the entrance. In 1979, depths of about 3 feet were reported available to the dock.

Powells Creek, Mile 71.1W, has depths of 4 to 5 feet in the approach and 1 to 2 feet through the railroad bridge and for a short distance upstream. The fixed railroad bridge 0.3 mile above the entrance has a width of 40 feet and a clearance of 26 feet. An overhead power cable at the bridge has a clearance of 45 feet.

 Occoquan Bay to Chain Bridge

, Mile 73.8W, has general depths of 5 to 7 feet. The entrance is 2.5 miles wide between on the southwest and on the northeast; the channel is 0.3 mile off High Point. A manmade rocky islet, 5 feet high, is near the center of the bay, 1 mile westward of High Point. The bay has little commerce; it and its tributaries are used as an ice harbor when the river channel is closed above.

Neabsco Creek, at the southwest side of Occoquan Bay north of Freestone Point, has depths of 4 to 2 feet. The fixed railroad bridge over the mouth has a 30-foot span with clearance of 33 feet. The overhead cables just west of the bridge have a clearance of 36 feet. Gasoline, diesel fuel, ice, water, a pump-out station, berthing with electricity and marine supplies can be obtained at the small-craft facilities on the south side of the creek above the bridge. Hull, engine and electronic repairs can be made; lifts up to 20 tons.

Belmont Bay, the northeastern arm of Occoquan Bay, has general depths of 3 to 4 feet. Belmont Bay is said to be rocky throughout; the rocks are covered at low water except during northwest winds.

empties into the head of Occoquan Bay along the west side of Belmont Bay. A marked channel with dredged sections leads through the bay and river to Occoquan. In 2013, the controlling depth was 7 feet from the entrance in Occoquan Bay to Light 14. The channel is marked through Occoquan Bay to the first bridge over Occoquan River.

Three fixed bridges, the Richmond, Fredericksburg and Potomac Railroad bridge, and the two U.S. Route 1 highway bridges, with a least clearance of 44 feet cross Occoquan River 3.6 miles above the bay entrance. Piles extend out into the channel on both sides of the first bridge. An obstruction, covered 1 foot, is on the north side of the third bridge, in about the center of the river. The twin I-95 fixed highway bridges, 4 miles above the entrance, have a clearance of 44 feet. The State Route 123 fixed highway bridge, 5 miles above the entrance, has a clearance of 42 feet. A rock awash is on the north side of the bridge in the center of the river. A power cable just northwestward of the bridge has a clearance of 44 feet.

Occoquan, on the southwest side of Occoquan River 5 miles above the bay entrance, is the head of navigation. Channel depths off the Occoquan bulkheads are 7 feet in the east half and 5.5 feet in the west half of the channel in 1991. Small-craft facilities, on the southwest side of the river above the first bridge, can provide gasoline, water, berths and marine supplies. Hull and engine repairs can be made; lift capacity to 25 tons.

Indian Head, Mile 75.3S, is a high wooded bluff. The town of Indian Head is back of the bluff. The lower wharf has depths of 12 feet off its northern face, and the small-boat basin on the lower side has depths of 4 feet. The upper wharf has depths of 12 to 15 feet at the face. Landing is permitted at either wharf only in case of emergency. Mariners are advised to use caution in the vicinity of the upper wharf because divers may be training in the area.

, Mile 77.3W, is a tiny islet marked by a clump of trees and surrounded by an extensive shoal. Between the islet and the Virginia shore is a narrow unmarked channel with depths of 7 feet.

, Mile 78.0E, has depths of 7 to 3 feet in the entrance but little water inside.

, Mile 80.0W, has depths of 3 to 5 feet in the entrance and 5 to 7 feet inside. The peninsula between Gunston Cove and Dogue Creek, 2 miles to the northeastward, is a part of the U. S. Army reservation of Fort Belvoir.

The small-boat basin and facilities at Whitestone Point, on the north side of the Gunston Cove entrance, are part of Fort Belvoir and are not for public use. A restricted area is off Whitestone Point. (See 33 CFR 334.250, chapter 2, for limits and regulations.)

Pohick Bay and Accotink Bay, which joins at the head of Gunston Cove 2 miles from the entrance, have depths of 2 to 3 feet for about 0.5 mile from the junction. Pohick Bay is foul with submerged duckblind and fish stakes. Parts of both bays are within the danger zone of a target range. (See 33 CFR 334.230, chapter 2, for limits and regulations.)

, Mile 81.9W, is used by small craft. A privately marked channel leads from the river across the northwest part of the estuary to the mouth of the creek. In 1980, reported depths in the channel were 3 feet, with 1 to 5 feet in the creek. The extreme north corner of the estuary is foul with grass and submerged duckblind stakes.

, Mile 82.3S, formerly an amusement park, has a wharf with about 10 feet reported alongside.

, the home of George Washington, is at Mile 83.2N. The custom of tolling the ship’s bell while passing Mount Vernon is said to have originated the night of Washington’s death, December 14, 1799. The buildings are open to the public daily from 0900 to 1700 during the summer and 0900 to 1600 during the winter. Excursion boats operate between Mount Vernon and the city of Washington, DC. A buoyed dredged channel leads to Mount Vernon wharf.

, Mile 83.9N, has depths of 2 feet in the approach and about 4.5 feet in a narrow channel, sometimes marked by private buoys, for about 0.6 mile above the entrance. A stone-arch bridge over the entrance has a clearance of 22 feet for a center width of 25 feet.

, Mile 85.4S, has depths of 1 to 3 feet. Some marine supplies, gasoline, diesel fuel, berthing with electricity, water, ice and a pump-out station are available at a marina on the north side of the creek 0.5 mile inside the entrance. Approach and alongside depths were reported at 5.5 feet. Hull and engine repairs can be made; lift capacity, 30 tons.

, Mile 85.8E, was built early in the 19th century for the protection of the then new nation’s capital; the fort is now a unit of National Capital Parks. There is a light on shore at the fort.

, Mile 88.0E, has depths of 2 to 4 feet. is on the north side of the entrance. The creek is little used.

, Mile 89.4E, is wooded and prominent. Only piles remain of the wharf just below the bluff.

Along the Virginia shore, about 2 miles south of the historic Jones Point lighthouse, a 2,500 feet breakwater structure follows off the shoreline around Dyke Marsh Wildlife Preserve. Another lighted breakwater extends 1,500 feet from the shore to () outer end.

Hunting Creek, Mile 90.0W, has depths of 1 to 4 feet. Fixed highway bridges cross the creek 0.6 and 0.9 mile above the entrance. The lower bridge is a three-arch structure with a width of 44 feet and a clearance of 9 feet for a width of 20 feet; the upper bridge has a clearance of 3 feet. Piles marking an abandoned channel are in the north part of Hunting Creek entrance. Numerous tree trunks, logs, wrecks, mudflats and other obstructions are in the entrance to the creek.

On the Maryland shore, opposite Hunting Creek, is the large building complex of National Harbor. A channel leads to a basin and marina at the harbor from the main channel in Potomac River in the vicinity of Rosier Bluff. The channel is marked by lights and daybeacons. The marina can provide gasoline, transient berths, electricity, water, ice and pump-out facility.

Jones Point, Mile 90.5W, is on the north side of the entrance to Hunting Creek and at the lower end of the Alexandria waterfront.Woodrow Wilson Memorial Bridge, Mile 90.7, which connects Jones Point with the Maryland shore, has a bascule span with a clearance of 76 feet; a sound signal is at the channel span of the bridge. (See 33 CFR 117.1 through 117.59 and 117.255, chapter 2, for drawbridge regulations.) Rocks are on the western edge of the channel just southward of the bridge in about

, Mile 91.4W, has some waterborne traffic. Foreign vessels drawing as much as 23 feet unload newsprint and some general cargo.

Pilotage to Alexandria was discussed at the beginning of the chapter.

 Regulated Navigation Area

Security zones have been established in sections of the Potomac River, north of the Woodrow Wilson Bridge, continuing north to the Francis Scott Key Bridge and in the Anacostia River. These zones are not active at all times but are enforced during special events. (See 33 CFR 165.1 through 165.40 and 165.508, chapter 2, for limits and regulations.)

 Towage

Tugs are not normally required for docking and undocking.

 Quarantine, customs, immigration and agricultural quarantine

(See chapter 3, Vessel Arrival Inspections, and appendix for addresses.)

Quarantine is enforced in accordance with regulations of the U.S. Public Health Service. (See Public Health Service, chapter 1.)

Alexandria is a customs port of entry.

 Harbor regulations

Jurisdiction of the District of Columbia harbormaster extends upriver from Jones Point. Harbor regulations provide a speed limit of 10 mph when passing the wharf area of Alexandria, except in emergencies.

The Alexandria waterfront extends about 1.5 miles north of the Woodrow Wilson Memorial Bridge. Some of the wharves are owned by the Government; several of the privately owned wharves are open to the public by special arrangement. Depths of 20 to 25 feet are at the outer ends of the wharves; in places old piling is a hazard to approaching vessels. Robinson south and north terminals are 0.45 mile and 0.9 mile above the bridge, respectively; each has a 300-foot face with depths of 25 feet alongside. (For information on the latest depths alongside the facilities at Alexandria, contact the individual operators.) Water is available at most of the facilities; cargo is handled by ship’s tackle. There are no major repair facilities for oceangoing vessels at Alexandria; the nearest such facilities are at Baltimore, MD, and in the Hampton Roads area.

 Small-craft facilities

Small-craft facilities along the Alexandria waterfront can provide gasoline, diesel fuel, water, berths and marine supplies. Hull and engine repairs can be made; largest marine railway, 35 feet; lift, 16 tons.

, Mile 91.6E, has bare flats in the approaches and general depths of 1 to 3 feet inside. Sand dredges have cut channels through the flats and made holes inside, but local knowledge is needed to find the deeper water. The fixed highway bridge over the creek has a clearance of 19 feet.

is at Mile 92.1E. A privately buoyed channel with reported depths of about 12 feet leads to the point. Just northward is the Blue Plains sewage-disposal plant. The Government pier 0.4 mile above Marbury Point extends to deep water; use of the pier is restricted to Government vessels.

Fourmile Run, Mile 93.0 W is used only by very small boats and skiffs at high water. The outer basin is navigable for small boats, using care, local knowledge and the chart as guides. Airport landing lights extend 0.5 mile into the basin from the north side. The Washington Sailing Marina is in the cove on the south side of the basin just above the entrance. In 2000, the controlling depths were 5.8 feet (7.3 feet at midchannel) in the marina entrance channel, thence depths of 7.7 feet to 11.1 feet were in the cove, with much lesser depths along the sides.

Ronald Reagan Washington National Airport ccupies the extensive fill area on at Mile 94.1W. Many domestic airlines use the airport day and night.

is at Mile 94.0E. Submerged pile remains of former wharves extend out about 150 feet from shore in the vicinity of the point.

Washington, D.C., on the east side of Potomac River 96 miles above the mouth, is the Capital of the United States. Prominent from the river are the Capitol Dome, the Washington Monument, and the Lincoln and Jefferson Memorials.

Commercial traffic in Washington Harbor consists chiefly of petroleum products, sand and gravel.

 Tides and currents

Daily predictions for Washington are available from the Tidal Current prediction service at tidesandcurrents.noaa.gov. Currents are variable, but the set is usually in the directions of the channels, and there is little or no flood current during freshets; see the Tidal Current prediction service for specific information about times, directions, and velocities of the current for several places in Washington Harbor. Links to a user guide for this service can be found in chapter 1 of this book.

 Ice

Ice closes the river at Washington during severe winters, but power vessels keep the channels open during ordinary winters. During the highest freshet in recent years, the river rose about 11.5 feet above mean low water in Washington Channel.

 Weather

Washington summers are warm and humid, and winters are mild; generally, pleasant weather prevails in the spring and autumn. The coldest weather occurs in late January and early February. The warmest weather occurs late in July. There are no well-pronounced wet and dry seasons. Thunderstorms, during the summer, often bring sudden and heavy rain showers and may be attended by damaging winds, hail or lightning.

The average annual temperature in Washington is 58.0°F (14.4°C). The average maximum temperature is 66.7°F (19.3°C) while the average minimum is 48.9°F (9.4°C). The warmest temperature on record at Washington is 105°F (40.6°C) recorded in August 1997 and the coolest temperature on record is -5°F (-20.6°C) recorded in January 1982. Each month, October through April, has recorded temperatures below freezing (0°C) and each month, June through September, has recorded maximums in excess of 100°F (37.8°C). Records of the past 20 years show the average date of the last freezing temperature in the spring to be March 29 and the latest, April 16. The average date of the first freezing temperature in the fall is November 10 and the earliest, October 21.

The average annual precipitation at Washington totals 39.39 inches (1,001 mm). Precipitation is evenly distributed, with the spread between the wettest month (August) and the driest month (February) being only 1.48 inches (37.6 mm). The greatest 24-hour precipitation total is 6.11 inches (155.2 mm) recorded in June 1972.

Snowfall is moderate and averages 17.1 inches (434.3 mm) each year. Snow has fallen in each month October through April. The greatest 24-hour snowfall occurred in February 1983 when 16.4 inches (416.6 mm) accumulated.

Tropical disturbances occasionally, during their northward passage, influence Washington’s weather mainly with high winds and heavy rainfall, but extensive damage from this cause is rare. Six tropical storms have had a direct impact upon Washington since 1950. Perhaps the most noteworthy was hurricane Hazel in 1954. Hazel passed to the west of the District while transitioning from a warm-core to a cold-core system. The storm provided sustained winds of 68 knots with gusts to 85 knots over a three-hour period.

Occasional overflows from the Potomac River result from heavy rain over the basin, at times augmented by melting snow. In a few cases during cold winters, ice forms on the river, and, in spring, flooding is caused by ice gorges when the ice breaks up. The river is in tidewater, and above-normal tides associated with hurricane or severe storms along the coast cause flooding at times. Local flooding in the area is also caused by locally heavy rain. Some flooding occurs from one or the other of these causes every year on the average.

In using the Climatological Tables for the area note that recent observations have been taken at the National Airport, which is in a warmer part of the area. Minimum and maximum temperatures in nearby areas may be 8° and 5° lower, respectively, and rain and snowfall amount may be slightly higher away from the airport.

Pilotage to Washington, DC, was discussed at the beginning of the chapter.

 Quarantine, customs, immigration and agricultural quarantine

(See chapter 3, Vessel Arrival Inspections, and appendix for addresses.)

Quarantine is enforced in accordance with regulations of the U.S. Public Health Service. (See Public Health Service, chapter 1.)

Washington, DC, is a customs port of entry.

 Harbor regulations

The District of Columbia Harbormaster, who is the officer commanding the Harbor Precinct of the Metropolitan Police Department, regulates the operation, navigation, mooring and anchoring of all vessels within the waters of the District of Columbia and enforces all laws and regulations relating thereto. The person in charge of any vessel 26 feet or more long entering the harbor, shall, if he intends to remain over 24 hours, report the date and time of arrival without delay and shall also report immediately before finally departing to the harbormaster at the Harbor Precinct wharf, Maine Avenue and M Street, SW. or to any police officer under his command. Permission to anchor in the District of Columbia must be obtained from the harbormaster. Both the harbormaster and the police boat monitor VHF-FM channel 16; call sign KUF-703.

At Mile 94.2 is the junction of Potomac River with to the eastward, Washington Channel to the northward and Georgetown Channel of the Potomac River to the westward. The lighted junction buoy also marks the outer end of the shoal making southerly from , 0.4 mile north of the junction. Washington Harbor comprises the navigable waters upstream from this junction.

A dredged channel leads from the Potomac River off Hains Point into the Anacostia River to a basin off Washington Navy Yard, through the 11th street bridges, and to a turning basin about 2.2 miles above the Hains Point Junction Lighted Buoy (). (See Notice to Mariners and latest editions of the charts for controlling depths.)

Harbor regulations prescribe a speed limit of 6 mph between the entrance to Anacostia River and the Benning Road Bridge, a distance of 4.4 miles.

The waterfront of Anacostia River extends along the north side for about 3 miles above the entrance. The Washington Navy Yard Annex occupies the area just above the first bridge to the second bridge; depths at the easternmost pier (which is normally used for visiting vessels) range from 15 to 17 feet. Most of the other piers and bulkhead wharves are privately owned.

 Small-craft facilities

There are small-craft facilities on the north side of Anacostia River just above the mouth, between the third and fifth bridges and at Bladensburg, 7 miles above the mouth.

Washington Channel extends northward along the east side of Hains Point for 2 miles to the Fourteenth Street causeway. (See Notice to Mariners and latest editions of the charts for controlling depths.) The channel is unmarked above Hains Point. A fixed highway bridge at the upper end of the channel has a clearance of 37 feet.

Harbor regulations prescribe a speed limit of 6 mph upstream from Hains Point.

The waterfront facilities are on the eastern side of Washington Channel. Pier 5, 1 mile above Hains Point, has depths of about 23 feet at the outer end. The pier is the headquarters of the harbormaster and is used by the police and fire department. Pier 4, just northward, has depths of about 23 feet at the outer end; it is used by excursion boats. The municipal fish and fresh oyster wharves are just below the highway bridge, 1.5 miles above Hains Point.

Slips and minor repair facilities for pleasure craft are at the north end of Washington Channel. Hull and engine repairs can be made: lift capacity, 20 tons. Water, berthing with electricity and marine supplies are available.

is that part of the Potomac River between Hains Point and just above Chain Bridge. In 2007, the midchannel controlling depth was 8.6 feet to the George Mason Memorial Bridge, thence 11.2 feet at midchannel to the Arlington Memorial Bridge, thence 13.9 feet at midchannel to the Francis Scott Key Bridge at Georgetown. The channel from Key Bridge to Chain Bridge, about 2.7 miles above, has unpredictable currents and numerous shoals and rocks. This part of the channel is used by small craft with local knowledge; mariners are advised to exercise caution.

Georgetown Channel is crossed by eight bridges between Hains Point and Chain Bridge, Mile 101. All bridges have either fixed spans or drawspans fixed in the closed position. (See 33 CFR 117.255, chapter 2, for drawbridge regulations.) The minimum horizontal clearance of the bridges is 104 feet and the minimum vertical clearance is 18 feet.

The is on the northeast side of Potomac River 1.6 miles above Hains Point. A fixed bridge with a horizontal clearance of 12 feet and vertical clearance of 11 feet crosses the entrance; tide gates obstruct the entrance.

Directly across the river from the Tidal Basin is the Pentagon Lagoon. Depths of about 2 to 7 feet are available in the lagoon. A marina on the north side of the lagoon has depths of 5 to 8 feet. The fixed bridge over the entrance has a vertical clearance of 18 feet and a horizontal clearance of 46 feet. Complete berthing facilities, gasoline and some supplies are available at the marina. Hull and engine repairs can be made; marine railway, 30 feet. Boundary Channel, which extends northward from the lagoon between and the Virginia shore, is shallow and is crossed by several fixed bridges.

, under construction (2018), is 2.3 miles above Hains Point and 97 miles above the mouth of Potomac River. Harbor regulations prescribe a speed limit of 6 mph above the bridge.

, Mile 97.5W, is a park area. Boats should not attempt to pass between the island and the Virginia shore.

Francis Scott Key Bridge is at Mile 98.3. The stone piers of the former Aqueduct Bridge, just above Key Bridge, have been removed to a depth of 10 feet except for the one nearest the Virginia shore, which is 9 feet above water.

Chain Bridge, Mile 101, is the head of tidewater navigation on the Potomac River.

For planning, not navigation. Verify current information before departure.