Deep in 17th Century Bikini Bottom folk village, SpongeBob, wearing a sailor's uniform and working at Le Krabe Kroustillant, hears an angelic voice singing from far away. SpongeBob meets Ariel, daughter of King Triton and the two form a beautiful friendship. But the kingdom of Atlantica is threatened by Plankton who had a deal with the sea witch, Ursula to conquer the Seven Seas! SpongeBob, Patrick, and Ariel have to stop them and save the kingdom!
