The fictional ship here is USS Suribachi (LST-1181). On the other hand, in the real world of the US Navy, the true USS Suribachi (AE-21) was an ammunition ship, which served 1956-94, and the true LST-1181 was USS Sumter, a tank landing ship of the Newport class, which served 1970-93.
Rabb refuses a cup of coffee when he learns that the head (the toilet) is out of reach, on the other side of a jammed hatch. He's outside a cell in the ship's brig (jail). The cell would have a toilet in it.