How to not be that boat on the river?

So we were riding on the river the other day and some of the local high schools were having a rowing comp. I did my best to try to stay away from them, but it seemed like they were everywhere. Eventually we had a chase boat come up to us and nicely tell us that they were having a comp. didn't really tell us where it was OK to go and not bother them.

My question is what should I do in that situation. They were right in the area with the calmest water and there really wasn't any other place to go. I don't want to be that boat that everyone hates, but I wanted to board and didn't really get to.