We are sailing on Carnival out of Anchorage on July 9. I am anxious to see the sun all evening. That will be a highlight for me!
The sun goes down, but the sky never gets dark. It's sort of dusk until the sun comes up again. We had to pin the drapes of our Anchorage hotel room closed the night before the cruise, to try to get some sleep in a darkened room.
You'll have a great time.