46 C.F.R. § 141.375 – Visual distress signals.

(a) Carriage requirement. A towing vessel must carry a combination of day and night visual distress signals indicated in Table 141.370 of § 141.370 for specified areas where the vessel operates.
(b) Day and night visual distress signals. Hand-held red flare distress signals, approved under approval series 160.021 or 160.121, and hand-held rocket-propelled parachute red flares, approved under approval series 160.036 or 160.136, are acceptable as both day and night signals.
(c) Signals for day visual distress only. Floating orange smoke signals, approved under approval series 160.022, 160.122, or 160.157, and hand-held orange smoke distress signals, approved under approval series 160.037, are only acceptable as day signals.
(d) Limited geographic area. A vessel operating in a limited geographic area on a short run limited to approximately 30 minutes away from the dock is not required to carry visual distress signals under this section.
(e) Stowage. Each pyrotechnic distress signal carried to meet this section must be stowed in either:
1. (1) A portable watertight container carried at the operating station. Portable watertight containers for pyrotechnic distress signals must be of a bright color and must be clearly marked in legible contrasting letters at least 12.7 millimeters (0.5 inches) high with “DISTRESS SIGNALS”; or
2. (2) A pyrotechnic locker secured above the freeboard deck, away from heat, in the vicinity of the operating station.