MONROE, Mich. -- One of four fishermen rescued after they were found holding on to their 19-foot boat in western Lake Erie said a heavy catch of walleye may have led their craft to capsize.

Roy Letson, 52, of Charlotte said the men had about 20 of the fish stored in coolers Thursday evening when the boat capsized, taking their radios and safety equipment underwater

"Maybe we had too much weight on the front of the boat, we had our fish up there," Letson said. "We were all done, coming in."

Monroe County marine deputies spotted the men about 5:45 p.m. Friday offshore from Middle Sister Island, about 35 miles southeast of Detroit.

The men had spent nearly 24 hours bobbing atop their capsized fishing boat.

Shortly before being rescued, Letson said he was going to try to swim for Middle Sister Island.

"We were thinking if we got close enough, I could slip off the boat and swim toward the island and radio for help," Letson said. "I was hoping I could make it, I guess. We had to do something."

Letson said the men did a lot of thinking -- and praying.

"This was my first time being out on the lake fishing with these guys; I didn't say very much," he said. "I was just watching for waves, trying to stay awake."

Letson's wife Sharon said rescuers including the U.S. Coast Guard, Monroe County sheriff's deputies and Canadian authorities did a great job searching for the men.

"We're thankful for everyone that prayed with us as soon as the word got out," she said. "People started contacting prayer chains. Everyone who prayed with us, and for all the people who searched."

Douglas Whittaker, 76, of Eaton Rapids; Larry Vert, 64, of Lansing; Ron Miller, 63, of Eaton Rapids; and Letson all received medical attention Friday after being rescued, the Coast Guard said.

The fishermen left Sterling State Park in Monroe at 8 a.m. Thursday and had been expected back at the boat launch about 4 p.m. A family member notified the Coast Guard when the men hadn't returned by 10 p.m.

Boats, helicopters and other aircraft from the U.S. and Canada cooperated in the search.