Sport and fun
I don't know much about sports activities, especially how to call them. There are several places, where is possible to rent some kinds of boats and jet-ski. Price for jet-ski is crazy, i dont remember exactly, but i thought it was too much.
Then you can try parachute, which is tied to a boat, a round way was 250 KN, banana tied to a boat for 5 people is a bit cheaper and there are more stuff like this.
I think children must enjoy these activities a lot. Nothing to bring.