Marv and the Pool of Peril by Alex Falase-Koya

When ordinary boy Marvin wears his super-suit he becomes MARV. A superhero with infinite powers . . . 

Marvin and his friend Joe are at the brand-new super-spectacular waterpark - WAVE WORLD! But despite the excitement, Marv's reluctant to get in the water. Although Marv can swim, sometimes he gets struck by a fear of the water that he calls 'The Panic'.

Marv uses excuse after excuse to stay out of the pool. Then someone shouts 'SHARK!' Shark!? It looks like a supervillain is up to mischief again. It's time for Marvin to become MARV.

But, even as a hero, overcoming his fear of the water is going to be a challenge. Can Marv defeat supervillain Shadow and her army of robot sharks to save the day?