Just got back today from the Pacific Princess Cruise to Bermuda. There were 5 casual nights. One of those nights is Island night. There are no semi-formal nights. Just 2 formal and the rest casual. Its so informal that many of the men wore shorts in the dining room. Even during formal nights most men wore suits and not tux's. The women didn't get that dressed up either. My husband and I were very surprised. The hostess said thats how it is in Bermuda. Very informal. I hope this information helps. By the way we had a fabulous time. We were upgraded from a deluxe room to a suite. We were in shock. Can't wait for our cruise in Dec. aboard the Ocean Princess. 10 days!!!