Section 182.470 - Ventilation of spaces containing diesel fuel tanks(a) Unless provided with ventilation that complies with § 182.465 , a space containing a diesel fuel tank and no machinery must meet the requirements of this section. (1) A space of 14 cubic meters (500 cubic feet) or more in volume must have a gooseneck vent of not less than 65 millimeters (2.5 inches) in diameter.(2) A space of less than 14 cubic meters (500 cubic feet) in volume must have a gooseneck vent of not less than 40 millimeters (1.5 inches) in diameter.(b) Vent openings may not be located adjacent to possible sources of vapor ignition.(c) A vessel of not more than 19.8 meters (65 feet) in length, carrying not more than 12 passengers, with ventilation installations in accordance with ABYC H-32 (incorporated by reference; see 46 CFR 175.600 ) will be considered as meeting the requirements of this section.CGD 85-080, 61 FR 986, Jan. 10, 1996, as amended by USCG-2003-16630, 73 FR 65209 , Oct. 31, 2008