The Boston Marathon may be the city’s most revered sporting tradition, but it’s not the only storied endurance race that draws elite athletes to Boston from all over the globe. On August 14, an elite group of swimmers will compete in the Boston Light Swim, an eight-mile race across Boston Harbor.

Despite its name, there’s nothing “light” about the effort to complete the swim. The moniker comes from the starting location for the race, historic Boston Light on Little Brewster Island. After battling powerful cross-currents, boat traffic, and strong gusts of wind (but no sharks), the swimmers will finish at the L Street Bathhouse in South Boston where they will need to warm up as the harbor waters, even in August, can be quite chilly and wet suits are not allowed. This is old school stuff.

The Boston Light Swim dates from the early 1900s and is the “Granddaddy of American Open-Water Swims.” When 15-year-old Rose Pitonof completed the swim in 1910, it took her 6 hours and 50 minutes. (The story of Rose’s historic swim is detailed in Discovering the Boston Harbor Islands.) Depending on weather conditions, most swimmers these days take between three and six hours to complete the course, although the race record is under two-and-a-half hours.

While the swimmers must battle the elements, thankfully, they no longer have to brave a heavily polluted harbor. Along their route, swimmers pass Georges and Rainsford Islands, go underneath the Long Island Bridge, and cross between Thompson and Spectacle Islands. Too bad they won’t have much chance to soak in the scenery of the Boston Harbor Islands.

Many swimmers in the past have used this swim to prepare for an English Channel crossing. But if you’re more at home in the comfort of the kiddie side of the pool—or prefer to stay dry altogether—you can still participate in the Boston Light Swim by serving on support boats that offer food, drink, and lots of encouragement to the swimmers. Race organizers always need escort boats for swimmers with captains who know Boston Harbor and have seaworthy motorboats. All escort boat volunteers will receive $300 directly from the swimmer and an event T-shirt. For more information, visit the Boston Light Swim website.

While you’re there, check out the race’s colorful history. I love the photo of 1908 competitor Annette Kellerman being arrested on a Boston beach the year before for wearing a men’s one-piece swimsuit.