Sharkmen

Golden Age Origin
Professor Wallace Thornton – scientist behind the Nautilus atomic sub - is throwing an engagement party onboard his boat – the Seasprite - for his daughter Carole and Leslie Adams. The Sharkmen come on deck and kidnap Thornton, taking him into a steel capsule and then dragging it underwater.

Captain Flash theories that Thornton is still alive, so he and Ricky take another sub and paint it as the Nautilus. As predicted, the Sharkmen attack. Flash and Ricky put on scuba gear and fight them underwater. Flash is able to defeat the Tiger Shark and Killer Whale that they launch at him, but in the struggle Ricky is captured.

Flash follows the Sharkmen to their plastic bubble base, saving Ricky and the Professor and capturing all the Sharkmen but their leader – The Sharkmen are in fact just a gang in special suits. Upon returning the Professor home, Flash identifies Leslie as the leader - with the gang backing this up, since he double crossed them. Leslie wanted to marry Carole only to get close to her Father, so he could then sell the Nautilus plans to the highest bidder.

Powers and Abilities
The Sharkmen suits appear to have scuba gear hidden inside,

Golden Age Appearances
Captain Flash #3