I was 10 years old when I first saw Hell Boats at the drive-in movies with my dad. I have to say that the nude scene with Elizabeth Shepherd left a lasting impression on me. I've watched it again more recently in my 60s. And, like the other reviewer, I simply love this movie. There's nothing really special about the effects or the plot line. I think it is just the wonderful cinematography situated around the island of Malta, and the stunning screen presence of James Franciscus and Elizabeth Shepherd who do have a special chemistry, despite what I've read about them not getting along off camera. There's also something to be said about the uncomplaining matter-of-fact way that these naval officers go about doing their dangerous and thankless job.
Hell Boats is basically a poor man's version of higher production value films like the Guns of Navarone. That is not to say that the acting is subpar by any means. The main characters, Franciscus, Shepherd and Ronald Allen all hit the right notes of expressing loneliness, anger and an unfulfilled life which is amazing, considering the plot they had to work with. This is one of Director Paul Wendkos' best works if not his best.