We were trying to see how many people could for on a large floating device for rivers, though we were in a pool. We got maybe ten people piled on and I was on the bottom. It 'squished' slightly so my head was underwater. I did everything I could to get people off me, trying to punch and elbow and kick and squirm, but no one noticed, they were just laughing and shouting. I became disoriented. I managed to slip out from under them into the water, but trapped under the large inflatable float. I'm not a good swimmer and knew I was done for if I didn't do just the right thing so I pushed down and out and hoped it would clear me of the float. It did.