Fifty Fathoms Deep (1931)

A shady lady has an affair with one deep sea diver, marries his buddy and breaks up their friendship. Ere long, she cheats on her husband and runs off with an oily yacht owner. Shortly afterward the yachtsman scutttles his ship and she is trapped in a sunken ship beneath the deep blue sea, as is the first diver who got trapped trying to save her. Will the husband be able to rescue them both?