(CNN) – Two men are dead after a speedboat accident on the Potomac River, authorities said.
The Maryland Natural Resources Police identified the victims as James Melley, 49 and Garth Tagge, 61.
The crash happened during the Potomac River Radar Run boating event Saturday near Fairview Beach, Virginia — about 60 miles south of Washington, D.C.
The men died after their 36-foot catamaran flipped over and they were ejected from the craft.
Police said Melley was the driver of the boat and Tagge was the throttleman — who controls the speed.
High-performance boating news website speedonthewater.com reported that the men were on their second attempt down the river when the accident occurred.
The boat had apparently clocked a 170-mph run earlier in the day, according to the website.
The cause of the accident is under investigation.
Maryland authorities say they did not sanction a speedboat race on Saturday.
Melley and Tagge, both from Georgia, were well known on the so-called “Shootout” circuit, where they participated in fast-boat competitions.