Neptun
The main idea behind this game is to get people wet and cooled off on a hot day. It is essentially a large station game, with the stations being games played mostly with water. Start all of your kids out on the beach. Explain to them that it is so hot outside and that the gods of the water have become angered. Neptun, the ocean God, will emerge from the water as a very angry man. His wife can also emerge too if you so choose. Neptun will explain that he wants the kids to make camp as wet as possible.
This is where the station games begin. Kids will run around to different stations and receive points based on how well they do at the different games. The station leaders will have point sheets and will keep track of how many points each team receives at the station. At the end of the game the station leaders should count up the points for each group and determine a winner.