at least 10+. Sorry I did not measure it. Never thought the subject would come up.

When diving down on a hot water day, I would get COLD! Wish I could have held my breath a lot longer. We found different places varied. In a spot where the sea floor drops off rapidly close to where you are anchored, we found the difference to be greater. I would normally drop as much hose as I could, while still keeping the pickup at least a couple of feet off the bottom. Almost always sandy.

I was surprised by how much colder it was!

Greg