Word has gotten around since last September, when the D.C. Harbor Patrol began enforcing a regulation that requires windsurfers on the District waters of the Potomac to register their sailboards.
The Harbor Patrol says about 200 windsurfers now have registered their sailboards for use on the segment of the river that runs between Chain Bridge and the Woodrow Wilson Bridge. That's up from 30 a year ago.
While the weather remains fair, windsurfers take their place alongside sailboats, but there's still a debate about whether to allow the sport on the polluted river.
The District's corporation counsel decided in 1982 that windsurfing was more akin to boating than water contact sports such as water-skiing, and so was legal.
Still, windsurfers fall into the water with some regularity, and how much of a risk they run interests experts who monitor the river's pollution.
James Collier, chief of the water hygiene branch of the D.C. Department of Consumer and Regulatory Affairs, says the windsurfers face a "small risk factor" of illnesses ranging from slight stomach infections to hepatitis. But he says no one knows the exact risk.
Experts generally agree the gamble is greater after periods of heavy rainfall, when the city's storm sewers carry raw sewage into the river.