Sam
Had a similar problem on my 37.5 which was identified in the pre-purchase survey fortunately. We got a price concession, but the cost of repair which was significant was greater than the price concession.Our problem was in the bulkhead between the aft cabin and the compartment that houses the holding and fuel tanks. It resulted from water leaks through improperly bedded fasteners in the cockpit sole around the base of the steering pedestal and steering quadrant cover and took a long time to develop.I felt it compromised the strength of the hull (so did the surveyor) as that bulkhead provides lateral strength. Based on the conditions in which we use our boat, I felt compelled to fix it. It may not be a big problem with light use.Hope this helps.Gary WyngardenS/V Wanderlust h37.5