L'isola Degli Uomini Pesce (1979) / The Island Of The Fishmen (UK-import)
1970s Italian action horror directed by Sergio Martino. In 1891, military doctor Lt. Claude de Ross (Claudio Cassinelli) and a group of convicts find themselves shipwrecked on a mysterious Caribbean island. When several of the prisoners disappear, the doctor uncovers sinister experiments being conducted by a couple living on the island.