When the Navy learns that Japanese freighters are hugging the coast of Japan in order to evade US submarines, the Trigger is sent to the area to lay mines to force Japanese shipping out into deeper waters. While laying mines in dangerously shallow waters the captain of the Trigger gets to see a Japanese freighter hit one of the mines they just laid.
Laying mines off the Japanese-held harbor of Saigon was a tough job at best; but, with one of your own mines stuck in the torpedo tube and an enemy destroyer closing fast, it was a downright nightmare.
Fed up with his routine chores in the gallery, the cook of the USS Sunfish, Teddy Aldridge, requests an active combat station for the next engagement with the enemy. The ship's executive officer assigns him a Browning automatic rifle for use during surface action.
Submarine risks Japanese shore batteries to rescue downed airman less than a mile off coast of Japan. Then USN destroyers mistake submarine for Japanese ship. Galivan evades multiple attacks by "friendly" destroyers.