Hol Chan Marine Reserve, Belize
One of the western Caribbean's great delights resides roughly 20 minutes by boat from Ambergris Cay. On my first visit, I was mesmerized by dozens of nurse sharks, jacks, stingrays and grunts cavorting with snorkelers over turtle grass and reefs. Here, I have swum with the most substantial wild fish -- normally only seen by scuba divers -- in only 6 to 10 feet of water.
On-site secret: Float from the feeding area to the shallow reefs and discover a dreamlike setting of sun-dappled coral and tiny reef denizens. Keep an eye out for: eagle rays. On more than one occasion I've been thrilled to see a majestic spotted eagle ray soaring through the reefs.
When to go: all year, but check cruise ship schedules to avoid the busiest times; holchanbelize.org.http://www.cnn.com/2009/TRAVEL/getaways/08/10/snorkeling.spots/index.html