Now through July 24, you can fly from North America to the Caribbean on United Airlines using just 25,000 United Mileage Plus miles, rather than the usual 35,000. The Mileage Plus Saver Award Sale, which can save you 20 percent or more when redeeming miles for travel, is good on flights between Aug. 18 and Nov. 18.
United's Caribbean destinations include Antigua, Aruba, Bahamas, Barbados, Belize, Bermuda, Cayman Islands, Grenada, Jamaica, Martinique, Netherlands Antilles, Nevis, Puerto Rico, St. Lucia, St. Thomas, Turks and Caicos, USVI and the Dominican Republic. For more details, see the United Airlines website.
United certainly and unfortunately does not fly to Martinique and did not do so ever in this millenium.
The only US based airline currently offering this destination is American Eagle. Until late spring last year, there also existed some service from Atlanta (ATL) non-stop to Martinique (FDF). Air Canada plans to offer service from Montreal to FDF late starting November or December.