Submerged Sonic

Characters

 * Sonic
 * Tails
 * Dr. Robotnik
 * Grounder
 * Scratch
 * Surff
 * Princess Bubbles
 * King Saline

Plot
The episode begins underwater, with Dr. Robotnik in his robotic submersible, testing out one of the torpedoes on a rock formation. Robotnik explains that his next target is the underwater city of Labyrinth and he plans to claim its power pearl supply as his own. In the city's castle, King Saline is not at all pleased with his daughter, Princess Bubbles, who has been hanging out with Surff, a young surfer who is intent on joining the fight against Dr. Robotnik. Saline decides to banish Surff from the kingdom, much to the dismay of Bubbles. Bubbles and Surff manage to escape the king's wrath, but are far from safe as the sub smashes the city dome and captures the princess in the process.

Meanwhile, up on the land, Sonic and Tails are doing the dishes (Sonic manages to dry them all off in one-third of a second). Afterwards, they set out to stop the mad doctor. At first, they have no luck finding any traces of Robotnik, but when they bump into Surff, the young rascal explains that he is looking for a hero to help out. Surff explains about what Dr. Robotnik has done, and Sonic and Tails decide to help.

The three travel to the undersea kingdom in a paddle-sub. However, the trip is far from being a stroll in the park, since Robotnik's menacing machines are in the way. They manage to outmaneuver the robots and reach the city none too soon. Dr. Robotnik has a word with King Saline, telling him that he will harm Bubbles unless he accepts the doctor's wishes. As Saline is about to give in, however, Sonic and Tails bust in, along with Surff. Outraged, Saline has them all thrown in the dungeon, even after Sonic tries to explain their intentions.

In the dungeon, Sonic and Tails begin to question Surff's relationship with Bubbles. Surff tells them about how important Bubbles is to him, at which point Sonic says that they will not only rescue her, but also prove that Surff is a worthy hero. After busting the door down, the three escape the cell and set out to foil Robotnik's plans.

All the while, Dr. Robotnik prepares for the point where he will capture the kingdom's power pearls. From those pearls, Robotnik plans to build an unstoppable army of mechanical soldiers. After waiting for some time, Robotnik decides to launch an attack on Labyrinth. Just before he can start, however, he spots Sonic recharging the paddle-sub and goes after the hedgehog.

Before Sonic and Tails launch the sub, Surff decides to bring along some of the power pearls in case they might need them. Robotnik tells Grounder to fire torpedoes at the sub, but Surff manages to stop the missile by using the exploding pearls. Robotnik then tells Scratch to summon his Robo-Ray (a mechanical manta ray with a bad attitude). The Robo-Ray also proves to be insignificant, as Sonic uses his buzzsaw attack to halve the monster. Having had enough of Robotnik, Sonic formulates one more plan. Surff turns the paddle-sub to face Robotnik, and Tails grabs a few pearls. Seeing them coming back at him, Robotnik decides to ram them head-on. Tails finally launches the exploding pearls, dismantling Robotnik's submersible. Bubbles is then freed by Surff, and she rewards him with a kiss.

Back at the kingdom, King Saline pronounces Surff the commander of the Royal Labyrinth Defensive Force as a reward for courage and resource when fighting Robotnik. Bubbles is so proud of him. Surff asks Sonic and Tails if they would like to stick around, but they decline, as they are aware that Robotnik is likely to start plotting again.

Robotnik, Grounder and Scratch, having survived the exploding sub, have floated to the surface on a raft out in the vast ocean. The episode ends with Robotnik saying, "I hate that hedgehog!"