Didn’t they drain the canal once? If so, they could have been rollerblading on the concrete bottom in June. 
What?
Based on past experience, I can tell you that female toplessness may be legal in DC but there are quite a few cops who are not aware of that. I spent a couple hours in the waiting room of the DC jail waiting to bail out friends because of this.
I just want everyone to notice that a poster named x-ray vision posted that 
Don’t you mean womyn?? 
Don’t you mean womyn??
Even though I am not a lawyer, I can state categorically that toplessness, even total nudity, is perfectly acceptable anywhere within the jurisdiction of my house.
Unfortunately, no one has availed themselves of this right in quite some time. (I mean, other than me.)
Thumbs up to your choice of friends.