The Collaborative International Dictionary of English v.0.48:
Submarine \Sub`ma*rine"\, a.
Being, acting, or growing, under water in the sea; as,
submarine navigators; submarine plants.
Submarine armor, a waterproof dress of strong material,
having a helmet into which air for breathing is pumped
through a tube leading from above the surface to enable a
diver to remain under water.
Submarine cable. See Telegraph cable, under Telegraph.
Submarine mine. See Torpedo, 2