DULUTH — Six-foot waves, seasickness and little sleep did nothing to deter six marathon swimmers who on Wednesday morning completed a 48-mile Lake Superior relay from Split Rock Lighthouse to Duluth's Canal Park in less than 24 hours.
"Land feels so good," swimmer Michael Miller said as he set foot on the rocky beach next to the Lakewalk.
The group of cold-water swimmers — who didn't use wetsuits or other assistance — set a distance record for that route on the lake, where the surface temperature hovered around 63 degrees the last 24 hours. The swim was filmed for an upcoming documentary about the effects of climate change on Lake Superior.
Team members each took four one-hour shifts, monitored by crews in kayaks and sail, dive and Zodiac boats. Such a swim in one of the coldest lakes in the world wouldn't have been possible four decades ago, the swimmers said, with lake temperatures in general increasing several degrees over that time.
"Lake Superior is so precious ... but it's changing," said Craig Collins, a 64-year-old Minneapolis resident who finished the last leg of the relay at 7:30 a.m.
Winter ice coverage of the largest, coldest and deepest of the Great Lakes is related to its temperature. And while extremely high ice-cover years like 2014 still occur, Lake Superior is seeing a growing number of below-average years, along with more volatile storms and toxic algal blooms.
On this swim, waves with whitecaps were the biggest challenge, but also "amazing," Plymouth resident Karen Zemlin said.
"You could sometimes catch the top of that five-foot breaker and just feel like a dolphin," she said.