MOWSA currently offers several solo, sanctioned swims that challenge marathon swimmers over long distances in cold water.

Cross Cape Cod Bay, (p2p) – 19 miles (30.6K)
White Horse Beach, Plymouth to HErring Cove, Provincetown

Promoted by Harry Kemp as the American Channel Swim.

Russell Chaffee of Sayre, Pennsylvania, was the first to swim across Cape Cod Bay, setting the course we still use today with his gutsy and well-studied 1968 swim. Chaffee extensively researched the swim from Whitehorse Beach in Plymouth to Herring Cove in Provincetown. He even created a computer program during a sabbatical at Yale University to predict the currents in the bay. Those currents had prevented earlier swimmers from successfully completing the crossing, but Chaffee's unique position as a math teacher and computer scientist with a love of swimming and figuring out complex problems led to the breakthrough planning needed to make this swim a reality. 

Chaffee launched his 19-mile swim from Manomet Beach in Plymouth at 4 a.m. on Wednesday, August 14, 1968, capitalizing on the counter-clockwise rotation of currents in the bay. He finished at Herring Cove Beach, just south of Race Point in Provincetown, at 6:40 p.m., about 14 hours and 40 minutes later. The tide was going out when he got to P-town and said he had to “work like mad” to finish. Chaffee was 41 years old at the time.

What to expect

Temperature: 58 to 70 degrees F

Tides: Swims are planned to start with the ebb tide and hopefully finish with a flood tide. There is a light current that runs counter-clockwise in the Bay that should aid the swimmer.

Weather: Anticipate ocean swells, wind, waves, and overcast skies. The water may be glassy, or you may get four-foot swells. This is New England; expect it all.

Swimmer notes: This swim is usually attempted in August or September and starts and ends on sandy beaches, making entry and exit relatively easy. The water temperature is coldest at the start and finish, but it usually warms up a few degrees in the middle of the Bay. You'll be in the open ocean for the duration of the swim, so expect to encounter marine life. Great White sharks have returned to Cape Cod Bay in recent years, and we know they make their home there. They will be in the bay. Although they are present, MOWSA has never seen or encountered a shark during a swim. Nevertheless, we have a Shark Protocol that will be strictly followed during any swim in the Bay.

Dates with favorable tides in 2025: Please inquire for which days offer the best chance of success.

Read more about the history of P2P in OUTDOOR Swimmer Magazine.

Solo Records

Relay Records

Banner photo by Elaine K. Howley