We actually hit Martinique a few years ago..
We ended up disembarking.. paying a taxi driver on the pier $40 (for 2 adults and our 4 year old) and he gave us a 2 hour sightseeing trip around the island...and we were back on the ship with 4 hours before departure..
I remember the port being just...Blah.......not as pretty as most..
Hope you have a great cruise!
Carnival Miracle to Aruba/Curacao/Dom.Rep/Grand Turk - 3/11
Carnival Miracle to Panama/Belize/Costa Rica-1/10
Carnival Sensation to Bahamas - 8/08
Carnival Spirit to Acapulco/Zijuantenejo/Manzanillo- 2/08
Carnival Miracle to Bermuda/Newport,RI - 4/07
Carnival Legend to Jamaica/Grand Cayman- 4/04
Carnival Imagination to Barbados/Martinique/St.Maarten- 2/03
Carnival Victory to San Juan/St. Thomas/St.Croix- 2/01