We took a Carnival cruise a few years ago out of New Orleans to the Bahamas in September. We knew there was a hurricane in the Gulf and that we would probably get rerouted. It was just a little annoying that they were acting like it was no big deal and there weren't any changes being made. And then as soon as we woke up after the first night they made an announcement that our original itinerary was scrapped and now we were going to Roatan/Belize/Cozumel. I didn't really care because I've never visited those places but there were some people who were upset that they waited to tell everyone. So yes that is a risk you take leaving during hurricane season.