Fright Camp (Goosebumps Series 2000 - 8)

I lowered my head and started to swim slowly, steadily out to the white floating platform. I was four or five strokes away from it when I found something wrapped around my ankle. At first I thought it was a piece of seaweed, but then I felt it grip me. I thrashed the water with both hands. Let go but the hard, bony hand held on, tugging me underwater.