Relay game that's best played outside!
2 water jugs per team and 1 plastic cup per scout, scales
Put the scouts into teams and into lines, each with a paper cup. The lead scout has a jug full of water and the end scout an empty jug. On “Go!” the lead scout pours water into the next scout’s cup which is poured down the line and finally into the water jug at the end. When one team is getting close to using up all its water, stop the game. The team with most water in the jug at the end of the line is the winner. Use measuring jugs or, if the jugs are the same, you can weigh them.
From "1000 Fantastic Scout Games"