Thanks for the feedback and advice. Had not thought to carry a copy of the death certificate. I will actually be taking some of his and my mother's ashes. Since you were all so kind, here is the rest of the story:

Flying MCO-LAX to board a ship that makes the passage through the Panama Canal. He worked there as an engineer in the early 1950's. In his later years his memory faded but he could always remember the details of his time there. Had hopes of taking him on the cruise but that did not work out.