The Big Gun - S1.E17

The Solistan's want to take over the world by destroying the west coast of the USA with their attack sub.(big gun 1) Stingray destroys the sub before it can do any damage. Hungry for revenge, the Solistan's want to destroy Marineville so they launch Big Gun 2. Marineville survives & Stingray follows it back to it's deep sea base & with Marina's help they destroy the Solistan's.