I think this is a 80's horror movie, but I watch it on TV in 1992.
The story goes like this...
I remember 6 or 7 teens swimming in a lake close to a Floating wood platform in the middle of the lake, and they see a green liquid form Floating on the lake, and its moving toward us, like it is alive, and eat a boy, and all those others teens get up on the Floating wood platform in the middle of the lake to be save, but the green liquid form start eating people one after the other by breaking the Floating wood platform, and at the end there still one guy who's trying to swim to the shore and e did it, but e is sitting on the shore, close to the lake to get is breath's back, and the green liquid form make a wave and eat the last guy...

Please help me find that movie??

This could be a segment of Creepshow 2 called The Raft, based on the Stephen King short story of the same name.

Just beat me. Doh

This could be a segment of Creepshow 2 called The Raft, based on the Stephen King short story of the same name.

I agree, Creepshow 2 (1987) a trilogy of which one was The Raft.

Haha I've never seen it and even I know it's the RAFT by stephen king cause I've read it. And just to let you know, if you liked it, the book is MUCH scarier :D

It's a short story in his collection called "the skeleton crew"