The first thing I thought when I saw the webpage for this on IMDB was "Is THAT Gene Kelly and why does he look so tough?!". Yes, despite his pretty dancing boy image, sometimes Kelly made other films...tough films such as "The Black Hand". "Pilot #5" and this one, "Seagulls Over Sorrento" (also known as "Crest of the Wave"). I do appreciate how he didn't allow himself to be typecast....but did this abberation work?
This film was set in the present day...and it took me a bit to realize it was not a WWII picture. Some British submariners are working on a new explosive for their torpedoes and there is an explosion...killing their expert. Since no one else in the British Navy knows about this explosive, an American officer (Lt. Bradville....played by Kelly) is stationed on the Scottish island where the work is being done. He brings along two assistants....though some of the sailors seem taken aback with them...and it's a case of US versus THEM (much like in the film "The Devil's Brigade").
Despite being a military film, because there's no war going on, it's not an especially exciting movie. Now this is NOT to say it's bad in any way...but it's not action-packed and is much more cerebral than you'd likely expect. Well made and interesting.