46 CFR § 182.410 - General requirements.
(a) Starting motors, generators, and any spark producing device must be mounted as high above the bilges as practicable. Electrical equipment in spaces, compartments, or enclosures that contain machinery powered by, or fuel tanks for, gasoline or other fuels having a flashpoint of 43.3 °C (110 °F) or lower must be explosion-proof, intrinsically safe, or ignition protected for use in a gasoline atmosphere as required by § 183.530 of this chapter.
(b) Gauges to indicate engine revolutions per minute (RPM), jacket water discharge temperature, and lubricating oil pressure must be provided for all propulsion engines installed in the vessel. The gauges must be readily visible at the operating station.
(c) An enclosed space containing machinery powered by gasoline or other fuels having a flash point of 43.3 °C (110 °F) or lower must be equipped with a flammable vapor detection device in compliance with § 182.480.
(d) In systems and applications where flexible hoses are permitted to be clamped:
(1) Double hose clamping is required where practicable;
(2) The clamps must be of a corrosion resistant metallic material;
(3) The clamps must not depend on spring tension for their holding power; and
(4) Two clamps must be used on each end of the hose, or one hose clamp can be used if the pipe ends are expanded or beaded to provide a positive stop against hose slippage.