ObscureHollywood.net’s review published on Letterboxd :
An expedition hunting fossils of an ancient amphibian sails into mysterious Black Lagoon in the upper reaches of the Amazon River. Unknown to the members of the expedition, a living descendent of the ancient, man-like amphibian lives in the lagoon. This creature has never seen a human, and he is entranced by the female member of the expedition, especially after she goes swimming in a very fetching white bathing suit. Trapping the expedition’s ship in the lagoon, the gill-man attempts to carry off the woman, killing several of the men in the process.
Trapped in the lagoon, the surviving humans attempt to capture the gill-man as a prize specimen but soon realize that saving themselves must be their only objective.
A fun science fiction film, it is especially impressive in 3-D where the vegetation circling the lagoon seems to envelope the audience. Richard Carlson plays his usual stalwart hero, Julie Adams is seductive, and Richard Denning has an unusual role as the unpleasant leader of the expedition.
Seen at the TCM Classic Film Festival, 2018.