Marathon athlete Jim Dreyer from Byron Center plans to swim at least 31 laps across the Straits of Mackinac this week, swimming non-stop for 125 miles or more, to set a world distance record. The record-setting Great Lakes distance swimmer will once again swim unescorted.

He began his first crossing from St. Ignace Monday, August 28, at 9 a.m., though heavy morning fog in the Straits caused him to divert his swim, said Bob Dryer, a St. Ignace land crew member. The fog made it impossible to view approaching freighters. As a backup plan, Mr. Dreyer swam south to the end of the bridge causeway before returning to St. Ignace and then continued on toward Mackinaw City. By that time, the fog had lifted and by 2:30 p.m. he was nearing the south end of the bridge.

He plans to continue swimming the length of the bridge until he reaches the 125-mile mark, sometime on Thursday, depending on water currents and weather.

Though swimming alone, he has a radio to communicate with his land crews, if needed.

The event, which he calls "Dire Straits 125," will have Mr. Dreyer battling the Straits' cross current for an estimated 84 to 96 hours, without the support of an escort boat.

He is pulling a diver down buoy along with him that contains drinking water, liquid meals, and vitamins. He remains in the water as he touches the shoreline on each pass. Land crews on both sides of the bridge replenish his supplies, explained Shelley McLain, a Mackinaw City crew member.

While training for the event, he stayed awake for three days, she said.

At night he will wear strobe lights.

He averages about 1.5 mile per hour and each trip across the Straits is approximately five miles, crew members say.

"He's an amazing individual," said Al Dreyer, his cousin and a paramedic stationed with the St. Ignace crew.

In announcing his plans in June, Mr. Dreyer said he welcomed the challenge of the Straits swim, noting he has already swum across the five Great Lakes.

Mr. Dreyer has set 14 records while swimming across all five Great Lakes. Last year's Lake Superior swim set the world distance record for a self-sufficient swim as he pulled 250 pounds of supplies for 59 miles alone across Lake Superior.

He will attempt to set his 15th record while raising funds and awareness for the Big Brothers Big Sisters program.