blasts of a whistle. Strangers in vessels usually take a pilot on account of the narrow, crooked channels. The pilotage rates are given on page 264.

Tides. The mean rise and fall of tides is about 9 feet (2.7 m.) at Lynn.

Directions.-For directions for entering Lynn Harbor see the tabulated courses on page 276.

Revere and Winthrop are towns and summer resorts occupying most of the west and southwest sides of Broad Sound. At Revere Beach a breakwater has been built out from the shore on Cherry Island Bar, forming an anchorage for small craft, with depths of 4 to 6 feet (1.2 to 1.8 m.). Northward of the breakwater there is a long wharf built out to a depth of about 3 or 4 feet (0.9 or 1.2 m.) at low water.

Winthrop Head, a hill 103 feet (31 m.) high and covered with houses, is marked by a light-colored standpipe, the most prominent mark in this vicinity.

Shirley Gut, separating Point Shirley from Deer Island, forms an approach from Broad Sound to the northern part of Boston Harbor. The channel is narrow and has a depth of only about 4 feet (1.2 m.) at mean low water. It is used considerably by small yachts and fishing boats but is too narrow for vessels of any size. It is unmarked.

Deer Island, on the south side of Shirley Gut and separating Broad Sound from Boston Harbor, is described on page 255.

BOSTON HARBOR

The entire harbor is shown on chart 246 and the inner harbor on chart 248. The entrance, between Point Shirley on the north and Point Allerton on the south, is about 434 miles wide. A group of islands and shoals lie in and off the entrance, through which several channels lead. There is a depth of 35 feet (10.7 m.) to Boston through Broad Sound North Channel and less through the others. Great Brewster, 104 feet (32 m.) high, is the most prominent of the islands in the entrance.

Prominent objects. In approaching Boston on a clear day the outstanding landmark is the Boston Customhouse. It is a tall office building and towers above the adjacent buildings. The light-colored standpipe on Winthrop Head is prominent. A turreted tower on Nantasket Hill affords a good landmark when approaching that por

tion of the harbor.

OUTER HARBOR AND CHANNELS

Under this heading are described the approach channels and the islands and shoals from the entrance to President Roads. Hingham, Quincy, and Dorchester Bays are described under separate headings. Channels.-Three main channels, all obtained by dredging, lead through the shoals at the entrance to President Roads. There are several other channels of less importance used by local vessels.

Broad Sound North Channel leads from Broad Sound to President Roads from northeastward, eastward of Deer Island. It has

been dredged 35 feet (10.7 m.) deep and 1,500 feet wide and is well marked by lighted buoys.

In 1926 dredging was being carried on to deepen this channel to 40 feet (12.2 m.) in general, but 45 feet (13.7 m.) through rock, and to a width of 900 feet, except at the outer end, where it is to be 1,100 feet wide.

Finn Ledge, with depths from 25 to 29 feet (7.5 to 8.8 m.), lies on the northern edge of the outer end of North Channel. The ledge is marked by a red gas and bell buoy. Careful navigation is required here, especially in the case of an incoming vessel passing an outgoing vessel at the entrance to the channel.

Broad Sound South Channel leads from Broad Sound in a southwesterly and westerly direction to President Roads. It has been dredged 30 feet (9.1 m.) deep and 1,200 feet wide, and is well marked by buoys and lighted ranges.

The Narrows is the channel leading into Boston Harbor from southeastward, between Boston Lighthouse and Lovell Island on the northeast and Point Allerton, Georges Island, and Gallup Island on the southwest. It has been dredged 27 feet (8.2 m.) deep and 1,000 feet wide and is well marked. There are shoals with depths of 21 to 23 feet (6.4 to 7 m.) in the southeastern approach, which may be avoided in the daytime and with clear weather.

Shirley Gut, a narrow approach to Boston Harbor from northward, is described on page 250.

Hypocrite Channel is a natural channel leading between Green Islands on the north and Little Calf Island on the south. It has ample depth, but there are unmarked dangers, and the greatest draft that can be taken through it to Broad Sound South Channel at low water is about 18 feet (5.5 m.). It is not recommended for strangers. Black Rock Channel, leading into The Narrows from eastward, between Great Brewster Spit and Lovell Island, has an unmarked ledge with a least found depth of 9 feet (2.7 m.) nearly in mid

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channel, which strangers may be unable to avoid. It is used only by small local vessels and is not recommended for strangers.

There is a channel 250 yards wide, leading into The Narrows from westward, between Georges Island and Gallup Island. There is a light near the end of the shoal off the southeast end of Gallup Island. This channel is suitable only for quick-working vessels on account of the sharp turn into The Narrows.

The Nubble Channel, leading from Nantasket Roads to President Roads between Nix Mate and Long Island, has been dredged 15 feet (4.6 m.) deep and 300 feet wide and is well marked by buoys and a beacon. The course through the channel is about 335° true (N. by W. mag.), heading about 100 yards to the left of Deer Island lighthouse and following the buoys.

Sculpin Ledge Channel leads between Long Island and Spectacle Island, and is good for vessels of about 8-foot (2.4 m.) draft to Hingham Bay by the passage southward of Peddock Island. The deeper water favors Long Island, and in coming from President Roads the island should be followed at a distance of about 1/4 mile until up with the red buoy off the easterly end of Sculpin Ledge. Pass close eastward of the buoy, and round the southwesterly end of Long Island at a distance of about 400 yards.

The channel leading from Nantasket Roads to Boston, southward of Long Island and Spectacle Island, is partially marked by buoys, and can be used by boats of 8-foot (2.4 m.) draft with the aid of the chart. Directions to Hingham Bay through this channel are given on page 275.

Boston Lightship, off the entrance to Boston Harbor 6 miles eastward of Boston Lighthouse, has a red hull with "Boston" on each side and a red and black mast surmounted by red gallery and lantern. The light is flashing white (every 3 seconds), 48 feet (14.6 m.) above the water, and visible 11 miles. The fog signal is an air siren (blast 3 seconds, silent 17 seconds). A submarine bell strikes “ 5–4 ” every 18 seconds. The radio fog signal sounds groups of 1 dash and 1 dot for 60 seconds and remains silent for 120 seconds. The call letters of the lightship are BAGY, but the station does not maintain radio communication.

Thieves Ledge, with 4 to 6 fathoms (7.3 to 11 m.) over it, is 3⁄4 mile long and about 1/4 mile wide. It is dangerous in heavy easterly gales, when the sea breaks on it. The ledge is marked northward of its eastern end by a whistling buoy, which lies 25% miles east-southeastward of Boston Lighthouse. There are spots with 534 fathoms (10.5 m.) over them lying 11⁄2 mile eastward and 1% miles southeastward of the buoy, upon which the sea sometimes breaks in heavy easterly gales.

Harding Ledge, 23 miles southeastward of Boston Lighthouse and 12 miles from the shore, is an extensive ledge, bare at low water, and marked by a spindle on its shoalest part, and a black gas and bell buoy 3% mile northeastward of the spindle. There is a rock, bare at low water, 300 yards southwestward of the spindle, and very broken ground, not closely examined, between the ledge and the shore westward. Vessels should keep outside the gas and bell buoys.

Point Allerton has shoals extending eastward and northward from it. A black gas and bell buoy placed northward of the point

marks the extent of the shoals. Ultonia Ledge, the eastern end of the broken ground, has very broken bottom and unmarked spots, with depths of 334 fathoms (6.7 m.), 34 to 11⁄4 miles eastward of the point. Point Allerton beacon (black cone on granite pyramid) is 350 yards northward of the point and near the end of the part of the shoal, which is bare at low water.

Boston Lighthouse, on the north side of the entrance to Boston Harbor from southward, is a white conical tower on a small island. The light is flashing white (flash 8 seconds, eclipse 22 seconds), 102 feet (31 m.) above the water, and visible 16 miles. The fog signal is a steam siren, sounding a group of two blasts, each of 3 seconds' duration, every 60 seconds. An auxiliary light, 13 yards from Boston Lighthouse, shows a fixed white light with two fixed red sectors covering the dangers in Nantasket Roads.

Shag or Egg Rocks are bare, rugged ledges lying 14 to over 12 mile eastward of Boston Lighthouse. They are surrounded by extensive submerged ledges.

Great Brewster, Middle Brewster, Outer Brewster, and Calf Islands are the larger of the islands lying northward and northeastward of Boston Lighthouse. Great Brewster is 104 feet (32 m.) high, has a bluff at the north end, and is the most prominent. These islands are surrounded by several smaller islands and extensive shoals, bare and submerged.

Great Brewster Spit, extending 1 mile westward from Great Brewster Island, is bare at low water and marked at the west end by Narrows Lighthouse (white dwelling on piles) and a beacon, and by another beacon (spindle on granite base) on the south side 14 mile eastward of the lighthouse.

The Graves are a group of bare rocks and ledges about 1/2 mile long in a northeasterly direction, and are marked near the southwest end by The Graves Lighthouse. Northeast Grave is a rock bare at low water 700 yards northeastward of the lighthouse. A gas and whistling buoy is moored about 1/2 mile northeastward of the ledge and 8 mile northeastward of the lighthouse.

The Graves Lighthouse is a conical granite tower. The light is group flashing white (flash 0.2 second, eclipse 1.3 seconds, flash 0.2 second, eclipse 4.3 seconds), 98 feet (30 m.) above the water, and visible 16 miles. The fog signal is a reed horn, sounding a group of two blasts, each of 3 seconds' duration, every 20 seconds.

The material from the dredged channels in Boston Harbor is dumped in Broad Sound 1 to 311⁄2 miles northeastward and northnortheastward of The Graves Lighthouse. A gas buoy and bell buoy, painted white and marked "DG," are maintained on the dumping ground, and are moved to indicate the locality where dumping is in progress. The only place where marked shoaling has occurred lies 112 miles 20° true (NE. by N. mag.) from The Graves Lighthouse, and this shoal has been removed to a least depth of 7 fathoms (12.8 m.).

Roaring Bulls, 11⁄2 to % mile southwestward of The Graves Lighthouse, is bare in the highest parts before low water and unmarked. Green Island, 114 miles southwestward of The Graves Lighthouse, is about 30 feet (9.1 m.) high, and is surrounded by several smaller islets and bare and submerged ledges.

Devils Back, 5% mile westward of Green Island, is bare at the northeast end at low water.

Lovell Island, on the northeast side of The Narrows and south side of South Channel, has several buildings, and the lights of the Lovell Island range (white conical towers) at the north end. Ram Head Flats and Ram Head (bare at low water) extend to a greatest distance of 34 mile northeastward of the island.

Nix Mate is an extensive reef on the south side of the eastern end of President Roads; near the center is a low grassy island marked by Nix Mate beacon (pyramid on granite base), and at its north west end is North Channel Front beacon (barrel on spindle on planked dolphin).

Gallup Island, westward of Lovell Island, is the site of the United States quarantine station. It has several houses and a wharf on the south side.

Georges Island, southward of Lovell Island and on the north side of Nantasket Roads, has a large fort and several houses. There is a wharf on the west side.

Nantasket Roads, westward of the southern entrance to The Narrows and southward of Georges Island, is a good anchorage. The depths range from 8 to 12 fathoms (14.6 to 21.9 m.). On the westerly side of Georges Island the depths range from 4 to 6 fathoms (7.3 to 11 m.), and better bottom and shelter will be found here in easterly winds. This anchorage is frequently used by vessels seeking shelter in easterly gales.

To enter Nantasket Roads follow the directions on page 272 for Boston Harbor to a position nearly 1/2 mile southward of Boston Lighthouse. Then steer 258° true (W. 14 N. mag.), and pass 250 to

.