Andy.........after seeing all of these responses, do yourself a favor.
Don't listen to anyone else, but your pediatrician, your husband and yourself.
That's all that really matters here anyway. If the doctor and you feel comfortable for the baby to travel, then so be it. No matter what you do, someone will have an opinion on it, so damm us all for giving any advice. Do what you feel is best and all will be fine.
Hope you and the family have a great cruise. Cruising with your children can be a really fun experience. Good luck!