The H.S.S. Terminus is Prof' Nakayama's Ship in Sir Hammerlock's Big Game Hunt Campaign Add-On
The H.S.S. Terminus is a location Sir Hammerlock's Big Game Hunt DLC in Borderlands 2
It is Professor Nakayama's ship
Professor Nakayama filled the ship with Eridium and research equipment. It crashed on the shore of Aegrus and Nakayama somehow managed to lock himself out of his own ship.