It looks for me more like a chaotic sailing than something organized I'm used to see in regattas - I believe, it must have been just the training turn
And why the *heck* is this private yacht searching his way between all those sailing boats? There was enough space all around the boats. Click in the picture to see closer that for me pretty dangerous looking situation.
But after all, it was a great and colorful sports event in front of a wonderful background: The Ravanel Bridge of Charleston. I love regattas!