by Creative Cutie
(United States)
Split everyone into 2 teams. Have half of each team go to the opposite side of the pool. The first person swims with the watermelon then hands it off to the next person on the other side of the pool. You keep on swimming and passing the watermelon to the next person. To win, your team has to finish first (each person on each team had there turn of crossing the pool with the watermelon).