Water Hoverboard

Although it doesn’t exactly work on land, this Marty McFly approved hoverboard does work on water, because it has power. The Water Hoverboard
($2,675), designed by Franky Zapata, utilizes the thrust created from
an attached large-bore water hose, which creates enough force to lift
the board and rider more than nine feet into the air. The hard part is
learning to balance, flip, and do other tricks without falling face
first into the water.