it's to talk about any sheet that comes trough your perverted head!!
I'm not a scholar of early Deathyspeak, but all that talk of sheets and troughs sounds vaguely nautical to me. So here's a nice picture of a sailing ship.
Lol, tens seems to have always understood what I meant since the very beginning on e-hentai xD. Even though my english sucked, and it still does in many ways X_X