(a) Except as otherwise provided in paragraphs (b), (c), (d), and (e) of this section, all engines must be water cooled and meet the requirements of this paragraph.
- (1) The engine head, block, and exhaust manifold must be water-jacketed and cooled by water from a pump that operates whenever the engine is operating.
- (2) A suitable hull strainer must be installed in the circulating raw water intake line of an engine cooling water system.
- (3) A closed fresh water system may be used to cool the engine.
- (b) An engine water cooling system on a vessel of not more than 19.8 meters (65 feet) in length, carrying not more than 12 passengers, may comply with the requirements of ABYC P-4 (incorporated by reference; see 46 CFR 175.600) instead of the requirements of paragraph (a) of this section.
- (c) On a vessel of not more than 19.8 meters (65 feet) in length carrying not more than 12 passengers, a propulsion gasoline engine may be air cooled when in compliance with the requirements of ABYC Project P-4.
(d) An auxiliary gasoline engine may be air cooled when:
- (1) It has a self-contained fuel system and it is installed on an open deck; or
- (2) On a vessel of not more than 19.8 meters (65 feet) in length carrying not more than 12 passengers, it is in compliance with the requirements of ABYC P-4.
(e) A propulsion or auxiliary diesel engine may be air cooled or employ an air cooled jacket water radiator when:
- (1) Installed on an open deck and sufficient ventilation for machinery cooling is available;
- (2) Installed in an enclosed or partially enclosed space for which ventilation for machinery cooling is provided, which complies with the requirement of § 182.465(b), and other necessary safeguards are taken so as not to endanger the vessel; or
- (3) Installed on a vessel of not more than 19.8 meters (65 feet) in length carrying not more than 12 passengers, in compliance with the requirements of ABYC Project P-4.
[CGD 85-080, 61 FR 986, Jan. 10, 1996, as amended by USCG-2003-16630, 73 FR 65207, Oct. 31, 2008]