A visitor to Lake Superior set off on a summer afternoon for a 22-mile voyage from the northeastern tip of Minnesota to rustic Isle Royale and then back again.

On a Jet Ski. Alone.

But fog soon got the best of the 42-year-old adventurer from suburban Washington, D.C., and a massive Great Lakes freighter plucked him and his personal watercraft from the lake nearly 30 miles south of the remote island.

Norma Roth recalled Dave Crevenston calling Grand Portage Marina early in the afternoon on July 8 and explaining his ill-advised plan.

"I told him not to try it," Roth said Wednesday, "And of course, he did it anyway. … He said he had enough gas for at least a round trip."

Roth said Crevenston "was somewhat prepared," wearing a wet suit and packing a life jacket when he departed about 4 p.m.

Roughly seven hours later and well after dark, the captain of the Canadian freighter Michipicoten was alerted by the U.S. Coast Guard about a disoriented personal watercraft user somewhere along the 689-foot ship's intended eastward path.

In an interview Wednesday, Capt. Jonathan Barnes said that Crevenston "managed to lock onto a weak cell signal to call his friend … and passed on his GPS coordinates. "

The Coast Guard got the message and relayed the coordinates to the Michipicoten "knowing we were close," the captain said.

With the help of a Coast Guard helicopter, the Michi-picoten crew located Crevenston "in good health" and lifted him and his personal watercraft off the water, the captain said.

The captain said Crevenston was lucky to survive his ordeal, noting that the air temperature at the lake's surface was barely above freezing at the time of his rescue. "He had already [fallen] into the water a few times that day," Barnes said.

Crevenston on Wednesday admitted "I was really nervous" about making the dash out to Isle Royale and back, even though he was riding a 300 horsepower Jet Ski that he described as "designed for going long distances."

"But you know what? I'm a safety guy," said Crevenston, whose itinerary on the vacation included visits to other lakes in Michigan. "If I get in trouble, I will turn around and come back."

After spending a few minutes admiring Isle Royale's coastline and clear waters, Crevenston said, he began his return to Grand Portage, but "for unknown reasons, this fog was so thick and dense. I couldn't see 5 feet in front of me."

Instead of heading west, Crevenston was floating south. He tried repeatedly to call for help as the wind forced him to climb into a cubby hole of the Jet Ski for warmth.

Crevenston was thrilled to see the freighter and didn't hesitate when he was instructed to make what he described as a climb 30 or so feet up a tiny ladder along the ship's exterior to the deck. The crew attached straps to the Jet Ski and brought that aboard as well.

Barnes said Crevenston "continued to thank us" during his 16 hours on the ship as it proceeded to its destination of Sault Ste. Marie, Ontario, on the eastern edge of Lake Superior and hundreds of miles from Isle Royale.

After being dropped off in Sault Ste. Marie, Crevenston took a flight east to Toronto before flying west to Thunder Bay, Ontario, 55 miles north of Grand Portage. From there, he paid about $160 for a cab ride back to the marina, where his adventure had begun.

"I'm embarrassed this happened," Crevenston said. "I have experience exploring lakes. The fog came in, and I became disoriented."

Paul Walsh • 612-673-4482