I have been Register  summer amp  on February   25 in Washington dc 
There's a river near by in Washington. You should check it out. It's called Potomac. I learned swimming there. When i'm tired while swimming or while teaching someone to swim. I'll float like a log in the river 
Yeah i know  little bit  about this  river  it  is  call The river s roaring back to life 
The flow of water is good enough. But you have to be careful around the deep areas though.
The best water  from that  river  is  middle Potomac sustainable flow .
It's kind of illegal to swim in some areas 
I have little  knowledge about  the  law  
But if you have proper training they'll let you off 
Yeah  i also know this But  the main thing is protect yourself when you swim lake  or  river  
I've been swimming since my childhood. so i know for a fact that i'd be safe