The Wave Runners

The US edition of The Wave Runners is known as Pirate Curse.

The pirates of the Caribbean have a name for kids who can walk on water - they call them polliwogs. As far as 14-year-old Jolly knows, she's the last polliwog still alive. She is valuable to the pirate captain who raised her, for she can sneak up on enemy ships by walking over the waves.

When someone sets a trap for Jolly's ship, Jolly alone escapes. She is washed up on a tiny island inhabited by a farming family - and the ghosts who labor for them. The farmers have a son, Munk, who has been raised almost in hiding. Munk longs to go to sea, but his parents say that they are afraid of pirates, and they have forbidden Munk to reveal his true identity - he, too, is a polliwog.

But pirates are not the only threat in the Caribbean. Evil forces are stirring, and a demon from the sea attacks and murders Munk's parents. Was the demon really after Munk? And Jolly, too? Why are the polliwogs so valuable, and who wants them enough to kill for them?
Jolly and Munk must sail with a strange crew of outcasts, led by the mysterious Ghost Trader, to avenge their loved ones and try to stop an ancient, malevolent force known as the Maelstrom.

What it will cost both teens, no one can tell.