Last Feb. we went to Cancun for a week and it wasn't warm enough for us. Snorkeling was very chilly. Any suggestions on a winter vacation spot that will be hotter?

This Jan and Feb were not really representative of typical Cancun weather - it was windier and therefore colder than usual.

The further south you go the warmer it is - however the further it is to travel and likely more expensive than Cancun. You could try Belize or Southern Caribbean islands.

Zanzibar is about as close to the equator as you can get. Obviously the further south you get, the better the chance of warmer weather and water. And islands surrounded by shallower waters will obviously have warmer water. The ABC islands in the Dutch Antilles are a solid bet as are St. Vincent and the Grenadines.

Buzios, Brazil, a hip resort town about 3 hours north of Rio -- as well as Angra dos Reis an hour south -- are literally and figuratively hot in Feb which is carnival season. Casas Brancas is a good pousada there. Lots of pocket beaches and strands with high 80s-90s temps and a fierce sun that can make your skin peel even if it's overcast.
The Seychelles in the Indian Ocean, particuarly Praslin, are also great destinations with reliable warmth/heat, a long flight through London or Paris but well-worth the
journey.

Make that Casas Blancas in Buzios/also Recife on the north coast and the deserted beaches in the north of Brazil or Olinda
near Bahia/Salvador are reliable heat -- and Brazilians have a zest for life unlike any other people I know.

If you go to the southeastern Caribbean, say Martinique on southward, you should have reliable over 80 deg. water, even mid-winter. The cold fronts never, ever get that far.

How is the weather in St. Maarten in Feb?

St. Martin, and anywhere in the NE Caribbean from Puerto Rico to Guadeloupe is reliably warm, with water temps. about 79-80.