In the UK - the Plimsoll Line.
Locks help ships move from one level to another
Armada
Skipper
Flotilla
A ship's waiter is a steward.
The correct term is "funnel".
A porthole (generally the round ones)
Trophic Level
Navy. Or if you want to go back in history, Armada.
Convoy
A boatyard is another name for a shipyard, a place where ships are built, repaired and restored.
The name of the ship that ships ships is "The Ship Ship."