Looks like 1977's Man From Atlantis, only with the Patrick Duffy character on steroids, and the rest of the cast on the amphetamine of the day.
I'd go see that.
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968)