I just recently came up with a game using the long tubular pool floats: Bokken tag. We used a nerf football and the tubes as bokken. The "It" person can only tag the other person by hitting them in the body with the ball. The only legitimate tag is to the torso-front or back. Anything below the belt on the arms or legs or above the shoulder does not count. The person defending can use the bokken tube (float tube) in any way to block the tag. I had them start out holding it like a bo. The can also attempt to knock the ball out of the "It" person's hand. The IT person cannot get up on top of them and must maintain at least the tube's distance.
The game helped them learn some blocking skills with the weapon and also getting off line, etc. It was actually harder to play in terms of making the tag since several were quite successful in blocking the ball.
I would have added this to the Aikiwiki but the teaching kids section did not seem to be there?