Yeah you went to the wrong location then when you examine the release tool it tells you where it is for ( also says in the popup message when you pick it up) , you need to first go around the ship on the deck, use the release tool you were rewarded with from the ghost puzzle on the storage room, find another release tool inside there and then go down and use that one on the door below. You first unlock the fish gutting knife later on, so that would be why you cant bring it out yet.