The Octavius was a naval ship under the command of Captain Hendrick van der Heul, William Kidd's former quartermaster. It was the first, and only, ship under his command. The vessel became stuck in ice during an expedition to locate the fabled Northwest Passage.
During the 1770s, the crew of a whaling ship discovered the Octavius off the coast of Greenland. The crew inside had frozen to death. The captain was found frozen midway through writing a log entry, dated to 1762. This means that the crew had died sometime around that date, and that during the intervening years between then and the 1770s, the ship had made its way through the Northwest Passage, apparently by itself. This lead to ghost stories springing up around the ship, and earned it a place in seafaring legend.
Connor, a member of the Colonial branch of the Assassin Order, discovered the Octavius in the ice and entered it, looking for a piece of Kidd's map. After he found it in Van der Heul's quarters, the ice cracked and the ship started its descent to sea bottom, though Connor managed to escape.