The description I recall from hearing about my dad’s stint aboard an aircraft carrier in Korea was that it was just a long, saltwater trough with seats suspended over some sections of it, with the waste just sent right back into the ocean. They used to play pranks like lighting a wad of toilet paper on fire atop a turd for the sheer amusement of hearing the guys downstream yelling as their butts and other rhyming appendages got singed one by one as it floated on down the line and eventually out to sea.
He was exactly right...I remember the same thing...LOL