Lights on United States naval vessels and revenue cutters. ART. 30. The exhibition of any light on board of a vessel of war of the United States or a Coast Guard cutter may be suspended whenever, in the opinion of the Secretary of the Navy, the commander-in-chief of a squadron, or the commander of a vessel acting singly, the special character of the service may require it. Distress signals. ART. 31. When a vessel is in distress and requires assistance from other vessels or from the shore the following shall be the signals to be used or displayed by her, either together or separately, namely: In the daytime— A continuous sounding with any fog-signal apparatus, or firing a gun. At night— First. Flames on the vessel as from a burning tar barrel, oil barrel, and so forth. Second. A continuous sounding with any fog-signal apparatus, or firing a gun. CHAPTER XIX LIMITS OF INLAND WATERS OF THE U. S. Inland waters on the Atlantic, Pacific, and Gulf coasts of the United States where the Inland Rules of the Road are to be followed; and inland waters of the United States bordering on the Gulf of Mexico where the Inland Rules of the Road or Pilot Rules for Western Rivers are to be followed. (All bearings are in degrees true and points magnetic; distances in nautical miles, and are given approximately.) Cutler (Little River) Harbor, Me. A line drawn from Long Point 226° (SW. by W. ⅞ W.) to Little River Head. Little Machias Bay, Machias Bay, Englishman Bay, Chandler Bay, Moosabec Reach, Pleasant Bay, Narraguagus Bay, and Pigeon Hill Bay, Me. A line drawn from Little River Head 232° (WSW. ⅜ W.) to the outer side of Old Man; thence 234° (WSW. ½ W.) to the outer side of Double Shot Islands; thence 244° (W. ⅝ S.) to Libby Islands Lighthouse; thence 231½° (WSW. ¼ W.) to Moose Peak Lighthouse; thence 232½° (WSW. ⅜ W.) to Little Pond Head; from Pond Point, Great Wass Island, 239° (W. by S.) to outer side of Crumple Island; thence 249° (W. ¼ S.) to Petit Manan Lighthouse. All harbors on the coast of Maine, New Hampshire, and Massachusetts between Petit Manan Lighthouse, Me., and Cape Ann Lighthouses, Mass. A line drawn from Petit Manan Lighthouse 205½° (SW. ¼ S.), 26½ miles, to Mount Desert Lighthouse; thence 250½° (W. ⅛ S.), about 33 miles, to Matinicus Rock Lighthouses; thence 267½° (WNW. ¾ W.), 20 miles, to Monhegan Island Lighthouse; thence 260° (W. ⅝ N.) 19½ miles, to Seguin Lighthouse; thence 233° (WSW. ⅛ W.), 18¼ miles, to Portland Light Vessel; thence 214½° (SW, ⅜ W.), 29½ miles, to Boon Island Lighthouse; thence 210° (SW.), 11 miles, to Anderson Ledge Spindle, off Isles of Shoals Lighthouse; thence 176¼° (S. by W.) 19½ miles, to Cape Ann Lighthouses, Mass. Boston Harbor. From Eastern Point Lighthouse 215° (SW. ⅜ W.) 15¾ miles, to The Graves Lighthouse; thence 139¼° (SSE. ⅜ E.), 7½ miles, to Minots Ledge Lighthouse. All Harbors in Cape Cod Bay, Mass.