While lights blink and extras turn important looking submarine-y knobs, Frankie Avalon plays a trumpet, Barbara Eden does the Charleston, and Peter Lorre does an impression of Debbie Downer while taking a shark for a walk in waist-deep water.
Men in scuba gear wrestle the phosphorescent rubber tentacles of a phony giant squid at the 56 minute mark, which is pretty exciting, then everyone sweats through their clothes. I don't know an awful lot about science, submarines, or the military, but I do know you shouldn't wear khaki when the temperature is 138 degrees and the sky is on fire. I bet that sub smells like all the armpits.
Often the submarine is everywhere but at the bottom of the sea, but the effects are pretty good for the time period, and there's no better excuse to watch a magnetic pre-Jeanie Barbara Eden.
No, you can't see her belly button in this movie, either.