We were in Cancun for Thanksgiving 2006, and our Cozumel snorkeling excursion was canceled due to high winds. We are headed back to Cancun this September 2007, and would like to try snorkeling again in Cozumel. Rather than paying for an excursion, we'd like to go on our own. Can someone give pointers on the best method to handle this on our own? Or, should we pay a tour guide and buy an excursion? Also, I've read about a couple of good locations, but was thinking about Chankanaab Bay. I've read that it's the best snorkel spot on the island. Would you folks agree or disagree with that? Anyway, let me know how you think we should go about a day in Cozumel from Cancun. Thanks!