The what is now named, Leucothea, was one of the many custom manufactured transport shuttles for a rich explorers capital ship. When that ship eventually went down (Due to Captain Drunk's unfortunate actions) it took the SG-09 with it. The SG-09 was salvaged from the shuttle bay along with various antiquities, and upfitted into a compact and quick scout submarine.
Check out my other submarine, the 'Bad Intentions' 40VO:
https://steamcommunity.com/sharedfiles/filedetails/?id=3662214384