I was on Hamelton the other night, think it was Tuesday night. I was bass fishing and got there at dark then fished till just before daylight. I put in at Hill Wheatly ramp and was headed back. Driving about 40, just cruising along when I saw what looked to be a cardboard box floating which I'd barely missed, didn't think nothing of it. About another mile down the lake I began letting off it to find the ramp when I saw a jet ski just floating aimlessly out in the middle of the lake. I swear if I'd been 5' more to the right I'd hit the darn thing out there in the dark. It kinda scared me at 1st so I went back to see if someone had fallen off, or worse yet if I'd hit anyone in the darkness. I made a circle around the jet ski and started to grab it and pull it in when I thought if someone see's me pulling this thing in they may think I stole it! I left it there thinking somebody probably just didn't tie it up good enough and with all the day traffic, lake patrol included someone will tug it in for them. I didn't even know where to take the darn thing? From now on it's life jacket hooked to the key when night fishing cause you never know what lurks in the darkness. I run off the navatronics so running aground wasn't my worry, it's all the other crap out there to worry about, like a jet ski out in the middle of nowhere!