I have a 38 ocean CC which had an identical leak. I went through the usual suspects, portlights, stanchions. But the leak was still there, bad as ever. Every time it rained there would be water collecting in the port side storage next to the water tank. The leak was at the port side, aft hull/deck joint, which is accessed by removing the teak rub rail. It was obvious where the leak was due to insufficient sealant from the factory, but dry as a bone after applying a bead of sealant.