46 CFR § 153.351 - Location of 4m vent discharges.
(a) At least 4m (approx. 13.1 ft) above the higher of:
(1) the weatherdeck; or
(2) any walkway that is within a 4m (approx. 13.1 ft) horizontal radius from the vent discharge.
(b) At least 10m (approx. 32.8 ft) from air intakes for, or openings into, accommodation or service spaces.