A family on a boating trip in Lake Michigan last week rescued a dog that was swimming alone 4 miles offshore, according to reports.

Jeannie Wilcox said she and her family were boating from Grand Haven to Frankfort last Friday when they spotted the dog in the middle of the lake treading water, according to NBC affiliate WOOD-TV 8.

Lake Michigan has an average depth of 279 feet and reaches 925 feet at its deepest point, according to the Great Lakes Commission. It's also 118 miles wide and 307 miles long, with more than 1,600 miles of shoreline.

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The family’s trip takes about 12 hours to complete.

Wilcox said they had been on the water for about eight hours when they came upon an alarming sight.

“I see this red animal in the lake, and I started screaming, ‘Dog in the water!’” she said, according to the station.

Wilcox said she believed the dog, a fluffy female mixed breed, had been in the water for at least an hour.

"We brought her up on our swim platform really easily," Wilcox told WOOD-TV. "We dried her off. She was obviously scared and cold."

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From there, the family traveled another four hours to Belmont, where veterinarians scanned the dog for a microchip and found the owners.

A short time later, the dog was reunited with them on the city’s docks, according to reports.

The couple had been on the lake in their own sailboat when the dog somehow fell in, WOOD-TV reported, adding the tags and microchip were critical in the dog’s safe return.

“I just hope that if this was my dog, somebody would do the same for me,” Wilcox said. “I would just be very grateful, happy because I know how rough Lake Michigan can be.”