I couldn't find one online. I did found one at a pond supply store. It can move up to a 1/4" of something solid .
This one can be in or out of the body of water.. I wish I had taken a picture of it while I was there. I believe it cost under $200.
I should be picking one up in a few weeks.
You can make a nice filter using a food grade 55 gallon drum ..
Research and buy a Dirty water pump..
Try to get one that can be used outside of the pool/pond
Its going to cost a little more but last much longer