Formal nights on the Western itinerary where Monday (day at sea) and Thursday (Lobster & Prime) Grand Cayman day 5 as you depart at 4 p.m. Wednesday, is Tropical night or Casual night. Wednesday is also a good night to book Portofino's or Chops. Neither restaurant requires a sport jacket or better but many men do wear one.
The ship is beautiful and very easy to get around. The hardest places to get to are the Sky Light chapel and the floating pool table. I know I saw it but can't remember where it was. The events on the Promenade deck are not to be missed. Take ship pictures if you desire on the first day on board, so you won't forget what rooms are where. Monday morning early is when you must get in line for Ice Show tickets right outside the main dining room, deck 3. That is a good day to enjoy a main dining room breakfast, too. Also don't miss Quest. Adults only but it is really hilarious.
Any questions, just let me know.