It is wise for married women to carry a mariage certificate as I have heard of incidents where a woman has been told that her name on her driver's license doesn't match her birth certificate which we all no will not if she has take her husband's name. Also, if you are sailing the southern Caribbean and going into Barbados, you will need a passport to board the ship. Word is that more and more Caribbean islands are thinking about requiring a US citizen to have a passport. For the cost, length of issue and the convenience of one ID, obtaining a passport is a very good idea.
Joe Canino CTC, MC