I think you are going to be a little far south, and have too much daylight. I'm on the Kenai Peninsula and we have a few nights a year that we really get good Northern Lights, always in the winter. A PP said they are not like what you see in pictures, but here in Alaska they are!! A few month ago we sat on the front porch and watched them rip through the sky, bright enough to read a book by...blue green and purple. They danced for about 45 minutes. I will see if I can find the pictures. I hope you get lucky on your cruise, it really is amazing!