Bobby, with today's security climate, the cruise lines are being more strict than before, and all their documentation indicates that it is your responsibility to make sure you have the proper forms of identification. In addition to a govt-issued photo ID (such as a driver's license),you need to have either an original or a certified copy of a government-issued birth certificate - not one from a hospital, etc. Sometimes these do not have raised seals, though they meet the official requirements otherwise (I had a client with an original w/o raised seal). If that is the case with yours, the cruise line employees should be able to accept it, though some may question it (as they did my client). Should you have an original b.c. that doesn't happen to have a raised seal, and the agent checking you in is not inclined to accept it, be sure to ask (politely) to speak with a supervisor.
If you have at least a couple months until you cruise, I recommend that you apply for a passport. Valid passports are much simpler to deal with, as you only need to carry one form of ID instead of two (i.e. birth certificate and govt-issued photo ID, such as a license.)