This was given as a gift to my nephew, and tried out at a pool. Did not think it would be as fun. Easy to wind up and if you start at the surface it will dive to the bottom and come back up. Can go quite a distance and very random turns, even lost it for a few seconds before it resurfaced. Also if you dive under and release it from the bottom of the pool you can hear the wirring going along.
Entertaining even for adults as it is for children.