A submarine is a sea-going vessel, both on the surface and under the water.
The vessel is a submarine.
In general, yes, a submarine is larger than a submersible. A submersible is usually considered to be a small craft operated from a support vessel.
submarine
A vessel that travels underwater is termed a submarine.
Submarine.
submarine
A submarine is a vessel that can travel both on the surface and under the water.
"Yellow Submarine"
The correct spelling is submarine (underwater, or a submersible vessel).
A submarine
The rathskeller vessel is the famous German u-boat submarine as the Americans called it that sunk various allied ships.
A submarine's main screw shaft length is totally dependent on the size of the vessel, but in general, anywhere from 30 to 50 feet.