The Gup-B is a shark-styled Gup with one seat. Known for its fast speed and acceleration, it is Kwazii's favorite Gup. He mainly uses it for almost all the missions the Octonauts go on, takes it out for solo missions, or to just have fun driving it around.
- High-efficiency bubble engine for smooth and fast travel.
- Overdrive engine for flank speed like the Gup-A (Turbo button).
- Emergency ejection seat (The Giant Kelp Forest).
- Camouflaging capabilities as a Tiger Shark (The Hammerhead Sharks, The Tiger Shark).
- Flying Fish Mode.
- Capable of leading dolphins, whether they're asleep or awake (The Spinner Dolphins, The Baby Dolphin)
- Peso (The Damselfish)
- Tweak (The Tiger Shark)
- Tominnow (A Very Vegimal Christmas)
- Pinto (The Great Penguin Race)
- Kwazii Cat (mostly)
- It is the fastest out of all the Gups. It seems to have a max speed around 70 mph, as it can keep ahead of a Pacific Sailfish.
- Some fish (like the Humuhumunukunukuapua'as) mistake the Gup-B for an actual shark and get scared. Even one of the Hammerhead Shark Pup Siblings saw the Gup (in Tiger Shark mode) and got scared.
- Kwazii said that he painted the shark teeth on the Gup-B himself.
- The Gup-B obtains retractable pectoral fins and a tail, as seen in The Flying Fish.
- Like Shellington with the Gup-D, Kwazii has an unexpected tendency to crash the Gup-B, especially when he goes too fast.
- Like the Gup-D, outside of flying fish mode, there is no visible way for the Gup to move forward.
- Although Kwazii is the Gup's default pilot, Peso and Tweak have been seen at the crafts wheel on a few occasions.
- In The Damselfish episode, Peso drives the Gup for the first time and calls it a "Getaway Gup". He feels nervous at first, but soon finds that driving it is pretty fun.
- In the Tiger Shark episode, as Tweak tries to avoid being eaten by Tom the Tiger Shark, the Gup-B is revealed to have a few modes. Although, she ended up crashing it in a cave.
- In The Spinner Dolphins, Kwazii was able to use the Gup to act like a spinner dolphin and lead the dolphins (while asleep and awake) out of the trash in the bay.
- Kwazii is very protective towards the Gup, not wanting to let it out of his sight, as seen in The Octonauts and the Ring of Fire.