Because of the submariners that built the space navy, even the modern navy “dives” into hyperspace and “rises” into normalspace.  The clarion call of a commanding officer to “prepare for surface action” is still the standard.  But not all their terms survived.  When the navy began building carriers and their escorts, they called on surface fleet sailors to man them.  And no true sailor would be caught dead living on a “boat.”  And subspace?  No.  Just no.