It definately floats, in the sea, cos when my oh and I were in the Carabbean, we rode on the beach and in the sea, and all the horses poo...d as soon as they went in the water.
It floats of course.
Hence why water treadmills have a little fishnet standing by (like you had when you were little) to fish the poo out. They also have to chlorinate them or they stink.
S
I didnt actually see the floaters till someone pointed them out..... but i do remember him plopping it out and the guy who was chucking sticks for his laborador called it out of the pond pretty quickly!!!!