Bava Batra 75: The Lights of the Leviathan and Jerusalem

More on the Leviathan. Among other details, the Leviathan can boil the water of the ocean. Also, it's very smelly. Also, -- all of which details have prooftexts, especially from the Book of Job, to back them up. Plus, a discussion of glory of the Leviathan and its benefits for the righteous. [Where's Where: Tzipori] Plus, a description of Jerusalem as part of the World to Come. Also, back to halakhah... Buying a ship, which is a "movable" item - which requires a formal proprietary act of acquisition. How far would one need to move it for that movement to count as your taking possession of the ship?