Wierd. I've never adjusted my FF to check it out but I DO KNOW that in Pelahatchie Bay, it's 11 or 12 feet is all. I was spider rigging and when I'd drop my bottom rig below 12 feet, my minners would be dead in about 5 minutes. That tells me where the thermocline is at. BTW, STAY OUTTA MY FESHING HOLE lol