Not a masterpiece, but a much better film than some of the reviews would lead you to believe. It goes on a bit too long, and Ernest Borgnine chews up every bit of scenery he can find, but Rock Hudson (not normally one of my favorite actors) is extremely convincing as the sub commander, and he and Patrick McGoohan (one of my all-time favorite actors) have unusually good acting chemistry. I first saw this in Cinerama, and it works very well on a huge screen, less so on TV.