Flyboarding was a word and a sport that I had not heard of until this afternoon.
It's a bit like a skateboard without wheels. A strong jet of water is fed from a boat or jet-ski through an umbilical and comes out of two nozzles on the bottom of the board.
It looks to be immense fun and experienced flyboarders can perform dives and somersaults in mid air.
Perhaps the best way to describe it is to look at the pictures of the two boys demonstrating their manoeuvres below.