Embarkation: Embark in Florida or Puerto Rico, or from a variety of ports along the East Coast (Boston; Manhattan; Brooklyn; Bayonne, NJ; Baltimore; Norfolk, VA; Charleston, SC.)
Ports: The main stops are the U.S. Virgin Islands St. Thomas, St. John, and St. Croix), St. Martin (French and Dutch sides), British Virgin Islands (BVIs — Virgin Gorda, Jost Van Dyke, and Tortola), Puerto Rico, and Grand Turk. Some ships also visit smaller islands like St. Barts, Antiqua, Anguilla, Les Saintes, and Dominica.
Highs: The beaches in St. John, the BVIs, St. Barts, Les Saintes, and Anguilla are idyllic.
Lows: Traffic jams up in St. Thomas and St. Martin due to thousands of cruise passengers (more than 10,000 some days) in port at the same time.
Recommendation: Small ships can call on quieter islands like Virgin Gorda and Les Saintes. If you're on a mega-ship, take a day trip to St. John from St. Thomas by ferry and enjoy the gorgeous beaches of the U.S. National Park land.
Embarkation: Most ships depart from Fort Lauderdale, Port Canaveral, Miami, New Orleans, Galveston, or Houston.
Ports: Western Caribbean itineraries include Cozumel and other points on Mexico's Yucatan Peninsula, plus Honduras, Belize, Grand Cayman, and Jamaica.
Highs: The Mayan ruins at seaside Tulum and farther inland at Chichen Itza are impressive. The reefs of Belize and Grand Cayman offer the best diving and snorkeling in the region.
Lows: On a single day in Cozumel, you might see more than 10,000 cruisers — and many seem to be drinking at Carlos 'n Charlie's. The throngs of snorkelers at Grand Cayman's Stingray City can be equally overwhelming.
Recommendation: Sign up for active, small-group excursions, such as horseback riding, tubing, bicycling, and diving tours. Also head for shops selling Mexican-made silver jewelry instead of the chain stores.
Embarkation: Most cruises sail from Barbados, St. Martin, or Puerto Rico.
Ports: Cruises exploring the lower part of the Caribbean tend to be longer than a week and hit some combination of the ABC islands — Aruba, Bonaire and Curacao — plus St. Lucia, Barbados, Grenada, and the little gems of the Grenadines, including Bequia and Mayreau.
Highs: The beaches in Aruba, Grenada, and the Grenadines are fantastic, and so are nature walks through St. Lucia's lush, green rainforest.
Lows: You're likely to have a longer flight and multiple connections to start your cruise.
Recommendation: The quiet islands of the Grenadines, with their clear waters, are a seclusion-seeking beach lover's dream. History buffs will love the longer itineraries that include a transit of the Panama Canal, through locks that, by gravity alone, raise ships over Central America and down again on the other side.