ObscureHollywood.net’s review published on Letterboxd :
On a Pacific island, an assorted group of passengers board a seaplane for a short flight to another island. The plane becomes disabled and crashes into the ocean near a seemingly deserted island. Exploring the island the pilot and passengers discover that it is the site for a hydrogen bomb test, and the bomb is set to explode in five hours. With tough guy Eddie Constantine in the cast, it is certain that these people will be saved, but, before that event, the film generates a good deal of tension (and some romance).