Todd dock steps polyethylene, do they float or sink?

[phorvati]

I recently boat Todd dock steps at a consignment store. Well being the dock rookie, i have not screwed them down and while I was at work, storm went by and steps were gone.

Does anyone know if they float?
They are polyethylene, but i see that there are several types and one of them does sink, which would be great. there is only 6 feet of water and no current where i am at at the moment.