Marathon swimmer quits after realizing he was going in the wrong direction: ‘What a blow!’

A 60-year-old athlete attempting to swim 80 miles across Lake Michigan had to throw in the towel on the third day after realizing he was heading in the wrong direction.

Jim Dreyer, who is nicknamed The Shark for his aquatic feats, blamed the watery goof on a malfunctioning GPS, which left him lost without a rudder.

“In the end, I believe it was something as simple as two AA batteries that prevented me from successfully completing a self-sufficient swim across Lake Michigan,” Dreyer said in an online post.

“It was an accident, but it was my fault,” he said. “This is a tough pill to swallow.”

Dreyer swam the length of the lake in 1998, when he stroked his way from Two Rivers, Wisconsin, to Ludington, Michigan — but has fallen sort of doing it again three times since last summer.

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This time he left Grand Haven, Michigan on Aug. 6 and aimed for Milwaukee.

He said he was well ahead of schedule on the second day, and hoped to make the swim in 60 hours instead of the anticipated 72 hours — and had just 23 miles to go.

Then things got bogged down.

“The batteries in the GPS on my supply craft were dying,” Dreyer wrote. “I got into my dry bag, found my bag of AA replacement batteries, and carefully placed it inside the supply craft to my left.

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“Turning to my right, I removed the old batteries, and then turned again to my left to get two new batteries from the bag,” he said. “THE BAG OF BATTERIES WAS GONE!”

Determined to keep going, Dreyer said he followed the setting sun and then the constellations — and what he believed was the glow of Milwaukee at the other end.

But with the city lights fading he found himself adrift.

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“It was a lost night both literally and figuratively,” he wrote. “I was lost in the middle of Lake Michigan. From sundown to sunrise, I mostly swam in circles and made almost no forward progress. What a lot of wasted effort!”

When his safety boat chugged up to tell him he was way off course, Dreyer was done — he was now about 47 miles from his destination, he said.

“What a blow!” he wrote. “The reality was that I was a little less than halfway across the lake after already swimming 60 miles,” he said. “This translates to a swim of over 100 miles and 100 hours.”

He called the botched swim “demoralizing” — but didn’t rule out trying it again.

“I can promise you that my mind is working on it,” he said.

With Post wires

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