their floating at a depth
That is the correct spelling for "submarine" (underwater, or underwater vehicle).
As regards torpedoes or missiles, yes, the submarine has weapons that can be launched underwater.
A valley that is underwater.
A submarine
A vessel that travels underwater is termed a submarine.
Submarine
Submarine
A submarine.
A valley that is underwater.
submarine
Underwater
Underwater volcanoes are called submarine volcanoes. They form in a similar way as their continental counterparts, that is close to plate boundaries.