Henry, your best bet would be to get a letter from your doctor, take it to your travel agent, have her e-mail or fax the letter to the special services department, keep a copy of the letter, bring it with you on your cruise, and seek out the Maitre D right away and present him with your situation and i am sure he would be able to accomodate your request, if he can't move you into traditional dining i am sure he would be able to get you a fixed time reservation in the open seating/anytime dining.