Mr. McConnell will finish at the Edgartown Lighthouse with a welcoming party at the Harbor View beginning Monday at 5 p.m.

Jeanna Shepard

Mr. McConnell will finish at the Edgartown Lighthouse with a welcoming party at the Harbor View beginning Monday at 5 p.m.

Jeanna Shepard

“It’s harder than anyone could even imagine,” said Edgartown harbor master Charlie Blair. “The currents are strong and the navigation is going to be very difficult. He’s going to get blown one way and then sucked the other.”

To track his progress, visit track.rs/ALongSwim.

Jeanna Shepard

To track his progress, visit track.rs/ALongSwim.

Jeanna Shepard

“All the shark sightings also make this one a little hairy,” Mr. Blair added. “But he’s wearing a deterrent device, so he should be okay.”

The purpose of the swim, Mr. McConnell said, is to raise awareness for Amyotrophic Lateral Sclerosis (ALS) and to raise funds for ALS research.

Mr. McConnell has been involved in competitive swimming since he was six years old. He started swimming at a Park District summer league in Chicago, continued throughout high school and walked onto the swim team at the University of Illinois, where he eventually became captain.

“But that was all pool swimming,” he said. “Open-water swimming is very different.”

Since he began long-distance open-water swimming in the mid-2000s, his life, career and passion for swimming have been inextricably linked to ALS and his drive to promote ALS research.

Mr. McConnell’s father died after a long battle with ALS in 2006. In 2011, Mr. McConnell partnered with his sister, Ellen McConnell Blakeman, to create A Long Swim, a nonprofit that both borrows the ALS acronym and is dedicated to raising funds for collaborative ALS research. Ellen also died after a 12-year battle with ALS in 2018.

“ALS is like a slow-motion shipwreck. It’s a neurodegenerative disease that slowly robs the patient of their ability to use their muscles,” Mr. McConnell said. “And the worst part of it is that there are no ALS survivors. When you hear that news, there goes with that an overwhelming feeling of powerlessness.”

He continued: “We met with the ALS researchers and learned quickly that we couldn’t help with their scientists. But we learned that the path to the cure would be paved with dollar bills, and we set out to do that in a creative way.”

Since A Long Swim was launched in 2011, Mr. McConnell has swum across Tampa Bay, the Catalina Channel, the Molokai Channel, looped around Manhattan Island and, of course, the English Channel — which is referred to as the Mount Everest of marathon swimming. For reference, approximately 1,800 people have successfully crossed the channel while over 5,000 people have summited Mount Everest.

The 127 miles of open-water swam by Mr. McConnell, not including training, have raised over $600,000 for ALS research.

Mr. McConnell said that he has seen incredible advancements in both research and awareness for ALS in the past decade. Most notably, researchers have discovered the root of the common cause for ALS that they hope will lead to finding a cure. The discovery, Mr. McConnell said, was announced just a few days after he landed on the Wissant shore of the English Channel.

Mr. McConnell has been preparing for his swim from Nantucket to Martha’s Vineyard for 14 months. Training has involved swimming an 18-mile stretch cumulatively each week and taking cold showers to build up his tolerance to the cold waters — wet suits are not allowed per the official swim rules and regulations set by the English Channel Swimming Association, which Mr. McConnell adheres to for all of his long swims.

Weather and other variables permitting he plans to set off at 8 a.m. on Monday, August 26, and arrive at the Edgartown Lighthouse around 6 p.m. A welcome reception at the Harbor View Hotel begins at 5 p.m.

“We’re trying to get to a point just after Muskeget by noon, because that is when the flood tide starts,” Mr. McConnell said. “That’s when we go through that rollercoaster when we get pushed south for a few hours. It really becomes kind of two swims. The first six miles to Muskeget and the next 12 are that roller coaster.”

Though he is the only one who will be in the water, Mr. McConnell said that he is just one part of the marathon swim team. He will be joined by a fleet of two boats and a kayak to aid him in his journey, though, according to long-distance swimming regulations, he is not allowed to make physical contact with the boat or anyone on it.

The core of his team, he said, is his family. His three sons and one daughter are all certified lifeguards and will be in charge of nutrition, stroke count, wildlife watch and social media. His wife, Susan, is the captain of the team and will be calling the shots.

“It’s not party time. It’s all nerves when we’re out there,” she said. “But we have a lot of confidence that he will make it.”

Much like long-distance swimming, ALS research is a marathon, not a race, that requires a team to be successful and only pushes forward stroke by stroke.

“Endurance and grit are incredibly important [for swimming],” Mr. McConnell said. “But I won’t even start to tell you the number of years ALS researchers have to endure to make it to their finish line.”

Mr. McConnell said he doesn’t plan to stop swimming until a cure has been found and an ALS survivor is waiting to greet him on the shore.

To follow Mr. McConnell’s swim in real time log onto track.rs/ALongSwim. To make a donation to ALS research visit alongswim.org/donate. Following the marathon swim, there will be a reception beginning at 5 p.m. at the Harbor View Hotel in Edgartown.