Section 169.608 - Non-integral keel cooler installations(a) Hull penetrations for non-integral keel cooler installations must be made through a cofferdam or at a sea chest.(b) Non-integral keel coolers must be suitably protected against damage from debris and grounding by recessing the unit into the hull or by the placement of protective guards.(c) Each non-integral keel cooler hull penetration must be equipped with a shutoff valve.CGD 83-005, 51 FR 896, Jan. 9, 1986, as amended by USCG-2000-7790, 65 FR 58464 , Sept. 29, 2000