Actually, as I have stated before in this and other attire threads, I believe men should be allowed to wear nice shorts to dinner. If women can wear cocktail dresses, why can men not wear nice shorts? It is the Tropics after all. No one has ever actually answered me on that one.
As for denim pants to dinner on
DCL? Jeans are now permitted completely on all "Cruise Casual" nights (meaning not semi-formal/formal). If you read this entire thread however, you'd probably be terrified to try because you may be seated with someone who thinks you are automatically beneath them because you do.

<--- That is to help protect me from the flames about to erupt.