There are many little tricks that can make maintaining a cruising boat easier.
One of them is that all doors should have hooks or latches to retain them open so that air circulates, and should be left that way as much as possible.
This one change can cut mildew growth and general mustiness way back.
I just added a hook to what we call the “mouse door” connecting the head and cockpit locker.
And, if we use a hook and eye, it’s a good idea to also add a second eye to retain the hook when the door is closed, otherwise it will make a very faint, but nonetheless hugely irritating, noise as the boat moves.
The one on the left, that I just added, is a better bet, because of the rubber insert that reduces clinking, than the one on the right, which the builder provided for the aft-head door.