Swimmers take part in the 2012 Washington Crossing in National Harbor, Md. (Denis Crean)

For Denis Crean and members of the WAVEONE Swimming club, chopping through the brown waters of the Potomac is a sacred rite of summer whether they’re participating in their annual swim from Virginia to Maryland or the weekly swims at National Harbor.

But earlier this month, National Harbor officials suspended “Sunset Swims,” which swimmers have come to count on as part of their weekly training routines. Crean said the decision has been devastating for the hundreds of open-water swimmers and triathletes in the area who rely on the Potomac to build endurance for their races and events.

“For the last three years, we have been swimming without any incident. We have a perfect safety record,” Crean said, adding that nothing can replace swimming in open waters. “I am a strong swimmer, and it is something to move through that water because you see things through a different perspective.”

Crean said many long-distance swimmers train in the Potomac, including members of D.C. Tri, Old Town Tri and Nation’s Capital Swim Club. The National Harbor swims were seen as vital to many triathletes because there are few open swim venues in the area.

In addition to competitive swimmers, Crean said, “some Thursday night swims will have as many as 20 Special Olympics athletes, Unified Partners and families members swimming with us at National Harbor.”

Swimmers take part in the 2012 Washington Crossing in National Harbor, Md. (Denis Crean)

But Angela Sweeney, spokeswoman for National Harbor, said officials there are not trying to prevent open-water swimming but are concerned with whether WAVEONE has provided adequate insurance to host the Sunset Swims, which last from May to September. Proper insurance, she said, ensures that the swims can continue.

“We have enjoyed our relationship with WAVEONE Swimming and are happy to welcome them back once they provide the necessary insurance and paperwork that is required for all activities taking place at National Harbor,” Sweeney said.

The cancellation of the swims comes as the region sees an uptick in interest in open swimming. The increase has largely been driven by an increase in the popularity of triathlons, which combine cycling and running with a long swim that often takes place in open water. Very often, swimming is a hurdle for many triathletes-in-training, and as a result, open-water swimming venues are essential for the competitors.

The cancellations have interrupted the beginning of the robust open-swimming season. On May 8, Crean’s group held its first “Sunset Swim,” complete with 54 swimmers. But soon after, members were informed they would have to suspend the swims until they could provide the proper insurance. The annual swim across the Potomac, known as Washington Crossing, is still scheduled for Sunday.

Crean said that while his group is excited about Sunday’s swim, he is unsure about when the Sunset Swims would continue.