Do you need a passport for eastern are western caribian cruise in 2012?

If you are a U.S. Citizen, and your cruise is a closed loop (starts and ends in the same port), you do not absolutely need a passport to cruise in the Caribbean. However, it is highly recommended, because if for some reason (like an emergency) you need to fly home early, you will need a passport. If you do not bring a passport, you must bring and official birth certificate and Government ID.

Given that passports for those 18 and over are valid for 10 years, go ahead and get the passport.