a linguitics question

Especially if the exit point is over water. And no danger of 'overspray' inside: No portholes anywhere in those days, especially in an area that might have to be used for ramming. And "head" would be correct for the hull members you describe.

Something just hit me about that location. In many old sailing ships, the Captain's cabin was at the stern and had windows facing aft. Would the Captain wish to have such stuff sailing by his windows? If they were able to be opened and he put his head out, there's also the view looking up when such a facility were in use.

Proper location of the exit point precludes the problem IMO.

Well, I pulled out my copy of The Lore of Ships and on page 40 it shows the afterbody of a 1768 Frigate. I saw no overhang. The top level, all the way to the aft is labeled as the "Great Cabin". I assume that's the Captain's cabin. I can't see all the common hands going thru the Captain's cabin to relieve themselves.

One of those 'exploded view' books (Stephen Biesty?). Every mode of transportation showed an occupied potty; the Mayflower-era ship showed a crewman sitting on the main deck aft on a sort of outhouse-without-the-house arrangment. IOW, outdoors, not in anyone's cabin.

Modern Queen Mary type is built for capacity, but sailing ships had/have to be 'streamlined' at both ends, which makes for a tapering forward from the aft end of the main deck downwards.

In any case, we're talking about some very primitive arrangments, whether at the bow or stern.

is in the general direction of the ship and is minimized. A bigger problem IMO is gusts, which are unpredictable. IOW time, tide and peristalsis wait for no man, so "Just do it".

Wouldn't that mean that the wind flow would be from aft to fore and the breeze (and smells) would tend to flow into a Captain's cabin located just below the "relief" point?