I had a similar issue in the aft head. I ran a small bead of clear silicone around the top of the baseboard. It has been a couple of years and has not leaked since.
With best regards,
Sailing Vessel - Cream Puff - SM2K - #275
Currenlty cruising – Warderick Wells – Exuma Islands, Bahamas
There is a storage space in the deck just outside the aft head. I noticed I had water in it, and found that the leak occurs when using the shower head if water hits the aft door jamb. At this location there doesn't appear to be any seal.
I plan to just add some silicone sealant there, but wondered if anyone else had noticed this? Is there a better way to fix it?