I'm not sure about other parts of the world but in South Africa there's a myth that black people can't swim - which is why I was (rightly or wrongly) surprised when I saw the three black trainee lifeguards to the left of this photo.
Now, obviously it's just silly to generalize like that, and even though the myth isn't true I'd have to guess that it holds at least some merit and that a much higher percentage of white people, vs. black, are able to swim.
I'd love some perspective on this from any of our black readers, so please leave a comment below if you have an opinion on the subject.