Balmar 912-75 and Universal 25xp

[Ray & Sandy Erps]

We had the same thing happen on our previous boat, an Islander.  It had the same door latch.  Fortunately, we always had the sliding port window cracked open a bit and I was able to reach in with a boat hook and unlock the door.  On a current boat, we have a small hatch in the ceiling for fresh air.  We leave that cracked open all the time too.  I guess if we ever get locked out of this boat's head, we'll resort to the old boat hook through the window strategy again.  Otherwise, it's pretty low on my list of concerns.  I suppose a person could install something under the sliding lock to prevent it from sliding down by itself, but require one more step to lock the door.  A small wood disk round drilled with an off center hole that would cam up against the slide lock might work and not look too ugly.

[hdevera]

Just a thought.  I keep the door to the aft cabin open with a short bungee cord attached to the stove bar.  Works great.  For the head, I keep it open underway with a hook latch attached to the door and chart area.  Doors are kept open unless someone is using area room.

[reedbr]

I installed 3" hooks on the doors to always keep them securely cracked open for ventilation.  
 
 As far as the lock, I had one mysteriously lock on us when I had a bunch of kids on board.  I couldn't unlock it with the boathook through the small hatch (MkII), so we took apart the handle.  There were screws on the outside.  I don't know what your latch looks like, but any locking mechanism can probably be disabled if you can remove the handle to work on it.