Sonic the Hedgehog and Tails are flying in Tails' airplane, searching for a mysterious energy signal that appeared on Tails' radar. They decide to follow this mysterious energy signal, and head out over the ocean. As they travel farther and farther across the ocean, a sudden storm approaches and blows them far off course. Tails loses control of the plane in the storm, and the two heroes crash land over one of the islands.
An energetic raccoon named Marine finds them, and tells them that they have landed on Southern Island. She explains to them about her dreams of building a ship to explore the world's oceans, as she wanted to do this ever since she was shipwrecked on Southern Island. Tails offers to help
rebuild her ship after she crashes it, since he's a mechanical genius and great at fixing things. He does this in hoping that she could also help him and Sonic find their way home.
Sonic sets off to explore the island for Materials to build a ship, and Tails starts to work on Marine's ship. Sonic returns, and discovers the smaller, faster ships that Tails and Marine had made. Marine, Sonic, and Tails try out the ships, and Sonic has a blast while racing across the seas. He soon encounters various islands and a sneaky band of pirates on their search for a treasure, lead by the notorious Captain Whisker. These pirates have treasure and loot in their sights, and they won't let anyone - not even Sonic the Hedgehog - stop them or get in their way. The blue hedgehog may be fast, and the pirates haven't slowed him down yet, they aim to knock Sonic out of their race for jewels and treasure.
Unexpectedly, as Sonic races through this chaotic world, Blaze appears. Blaze reveals to them that they've accidentally traveled to her dimension during the storm. It turns out she is after Whisker and decides to go along with Sonic, Tails, and Marine in order to find answers. Throughout their adventure, the heroes will travel through various islands and places, in search of clues and reasons about what's happening and if Sonic and Tails can ever find a way to return back home.
Sonic the Hedgehog
Any time something seems off, Sonic springs into action, as no doubt a bigger catastrophe is brewing. When he and Tails crash on Southern Island, he has the nagging feeling that it isn't an accident that they've landed there. If they don't act fast, he fears they might never get home - but that's before he realizes there are much bigger troubles to worry about.
Blaze the Cat
Blaze hails from royalty in an alternate universe and she's never without her purple cape, which thinly disguises her ability to use fire - they don't call her "Blaze" for nothing! When cornered by an enemy, she will throw off the cape and create a fiery inferno or shoot fire from her hands. She is the keeper of the Sol Emeralds and it's a task she takes very seriously. When she hears of the thieving pirates, she travels through the dimensions to investigate. She is as surprised to see Sonic as he is to see her and when she tells him her tale, they both realize there is far more at stake than they thought! When she collects all 7 Sol Emeralds her body become is covered in fire,even with her royal cape on.
Miles "Tails" Prower
This brilliant two-tailed fox,which he uses as helicopter propelers,is Sonic's best friend and a very skillful mechanic. When he and Sonic become stranded on Southern Island, Tails constructs ships that they hope will get them off the island. As Sonic brings him new Materials, he builds four widely varying ships. With these vessels, Sonic explores the surrounding islands - where he uncovers a whole heap of trouble!
Marine the Raccoon
Marine is a lovable raccoon child with an alstralian accent from Southern Island with a passion for the sea.Not thinking of herself as a kid,she makes everyone call her Captain.She builds the ship of her dreams so she can sail around the world. However, on the SS Marine's maiden voyage, Marine realized she forgot to add one vital part to her ship - the brakes! Tails offers to help her rebuild it, and she is so excited she doesn't know whether to laugh or cry - so, instead she just talks a lot. Sonic and Tails can't understand half the things she says, but she's a lot of fun to have around.
Captain Whisker
This surly pirate captain is used to encountering foes on the high seas, but Sonic presents him with some unique challenges: not only is he fast, he's also more fearless than most! The captain has a short temper, especially when he's being tested, but luckily his crew is fiercely loyal, and he's able to evade Sonic and keep up his search for the treasure.
Johnny
The right-hand man of Captain Whisker, Johnny is a big talker who doesn't like to lose - ever. He is most comfortable at sea and he is always seeking worthy opponents to race on waterbikes, but few are brave enough to challenge him until Sonic. Has Sonic met his match?