SHIP

A ship is a large, sea-going watercraft. A ship usually has sufficient size to carry its own boats, such as lifeboats, dinghies, or runabouts. A rule of thumb saying goes:
"a boat can fit on a ship, but a ship can't fit on a boat". Consequently submarines are referred to as "boats", because early submarines were small enough to be carried
aboard a ship in transit to distant waters. Often local law and regulation will define the exact size which a boat requires to become a ship. Compare vessel.
During the age of sail, ship signified a ship-rigged vessel, that is, one with three or more masts, usually three, all square-rigged. Such a vessel would normally have one
fore and aft sail on her aftermost mast which was usually the mizzen. Almost invariably she would also have a bowsprit but this was not part of the definition. The
same economic pressures which increased sizes to the point of carrying four or five masts, also introduced the fore and aft rig to larger vessels, so few ship-rigged
vessels were built with more than three masts. The five-masted Preussen was the outstanding example, but the big German ships and barques were built partly for
prestige reasons.