This movie was the first and only time that former American President and actor Ronald Reagan and wife Nancy Reagan (aka Nancy Davis) star-teamed and made a movie together. The couple however did appear frequently together in television episodes of General Electric Theater (1953).
The name of the Hellcat submarine in this movie that Ronald Reagan commands was the USS Starfish aka The Starfish. This was a fictional name and not the name of a real World War II US Navy Hellcat submarine. However, the type of name was in keeping with the style of fish and marine-like names of the real Hellcat submarines of the Second World War which were named as follows: SS 411 USS Spadefish; SS 401 USS Sea Dog; SS 291 USS Crevalle; SS 302 USS Skate; SS 282 USS Tunny; SS 283 USS Tinosa; SS 229 USS Flying Fish; SS 287 USS Bowfin; and SS 223 USS Bonefish.
The name Hellcats of this movie's title refers to the US Navy vessels which took part in Operation Barney and traveled through the mine-ridden waters that lead to the Sea of Japan. The Hellcats term is derived from the US Navy's slang word for mines belonging to the Imperial Japanese Navy: Hell Pots.
Towards the end when a Japanese ship is torpedoed, the footage of the explosion is of HMS Barham, torpedoed in the Mediterranean in 1941.
The "horns" on WW2 mines were filled with acid. When they were struck the acid was squirted onto the detonator causing the mine to explode.