Maybe not a goof, or gaff, but at one point when the plane is strafing them and the destroyer is after them, the camera does a quick sweep of the ocean, and you can make out a small island nearby. I thought they were supposed to be out in the middle of the Pacific by then, in transit to their op area.
Also, at one point when the command to dive the boat is given, one of the officers says "Dive!" three times. I learned from some other sub movie that the correct verbal order for "Dive" is to say "Dive" twice, not three times.
Also, in the IMDb cast list, Alan Hale, Jr.'s character is listed as Lt. Pat Malone, which would denote a rank of full lieutenant. IIRC, in the movie, he was promoted (after 15 years!?) from the rank of Ensign to Lieutenant j.g., not to full Lieutenant.
But of course these are minor quibbles. The important thing to look for in the movie was Andra Martin in a bathing suit.
A frequent error in submarine movies is sounding the diving alarm (klaxon) three times and announcing "Dive, dive, dive" on the 1MC (PA system). This is wrong. When diving, the klaxon is sounded TWICE and "Dive, dive" is announced. When surfacing, the klaxon is sounded three times and the announcement "Surface, surface, surface" is made.
(from a submarine veteran)
And roger that on the bathing suit!
I love sub movies! It was from the goofs board on "Destination Tokyo" that I learned about the proper command for Dive:
Factual errors: When the submarine first dives, the diving alarm incorrectly sounds three times with the announcement of "dive, dive, dive." The correct procedure for diving is two sounds with the announcement of "dive, dive," and surfacing is three sounds followed by "surface, surface, surface."
"I've always tried to teach you two things. First: Never let them see you bleed. Second: Always have an escape plan." — Q
I think that's what I said...