Thank you for your help. I'm mainly looking at the cruise because it goes to these ports during times when I might see the Northern Lights. There are overnights in a couple ports which would increase the likelihood, I believe. From what I've read, P&O may be a little more formal than what I have experienced on other cruise lines, including Princess. I know that Alaskan cruises tend to more casual. I wonder if this itinerary is similar?