Michigan - A long-distance swimmer who calls himself "The Shark" is ready to jump into a lake near the US-Canada border for a 30-hour swim while pulling a ton of bricks.
Jim Dreyer calls the brick-filled dinghies his "train of pain".
The 49-year-old began his 35km swim on Monday and plans to end on Tuesday in Detroit.
The holder of a number of world records for endurance swimming, Dreyer said he expects to set one this time for longest distance swimming while towing a ton of bricks - a record that doesn't currently exist.
"Nobody has ever pulled a ton of bricks any distance," he said. "Pretty surprising, right?"
He's doing it without a support boat. One of the dinghies is equipped with a radar target so Dreyer will show up on radar screens. He has to feed himself and won't leave the water until coming ashore.
Dreyer is swimming with a GPS tracking device that will post his position online. It also comes equipped with a messaging system. At the touch of a button, Dreyer can send out three pre-programmed messages.
One lets his crew know he's OK. A second tells them he's not and to send a boat. A third shows that he's in a life-threatening situation and requires immediate assistance from the Coast Guard.
Dreyer is trying to raise money and awareness for Habitat for Humanity.