Deck. "Hit the deck" = "Get on the floor" etc.
A Seaman is the correct informal term for a Navy officer. Informal term for a sailor in the US Navy is "bluejacket".
A "standard" hitch in the Navy is 4 years.
I haven't heard that term when relating to the US Navy. But in the Royal Navy SDG is a scubadiver
Nothing - Department of the Navy is the formal title for the Pentagon division that encompasses the U.S. Navy and the U.S. Marine Corps. Navy Department is an informal term.
Ajar is the term for a door that is slightly open.
The term "NAR" doesn't refer to a Navy ship - it's the standard Navy acronym for Naval Air Reserve.
term
geedunk
Perform To Serve.
There are no walls in the Navy, either on land or at sea - only Bulkheads.
The generic term for individuals in the Navy is sailor. As of the end of August, 2007, the approximate total of Navy personnel (officer and enlisted) was around 338,000.