In the midst of World War II, the battle under the sea rages and the Nazis have the upper hand as the Allies are unable to crack their war codes. However, after a wrecked U-boat sends out an SOS signal, the Allies realise this is their chance to seize the 'enigma coding machine'.
Bumbling Navy lieutenant Tom Dodge has been given one last chance to clean up his record. But Admiral Graham, his nemesis, assigns Dodge to the Stingray, a submarine that can barely keep afloat. To add insult to injury, the Stingray is to be the enemy flagship in the upcoming war games … and to make matters even worse, Dodge's crew is a band of idiots even more incompetent that he is!
On a US nuclear missile sub, a young first officer stages a mutiny to prevent his trigger happy captain from launching his missiles before confirming his orders to do so.