Pretty cool. A big water tank for flushing up above, or many smaller ones?
In 63 I sailed on the last sail rigged snapper smack on the Gulf of Mexico, an old 80 ft Mobile schooner left over from WWII when to sail, a commercial fishing boat had to actually sail because fuel was unavailable. Toilet facilities were either to stand at the rail somewhere aft of amidships or hang one’s posterior over the transom. The Peggy G had a large crew, eleven men. There were no women out there except rarely on one of the smaller diesel boats on which the captain’s wife went as cook and she shared the same facilities. There was no onboard equipment.
So how does the toilet on a submarine work? Where does it flush to?