I went to Alaska in May 2005, if I can answer any questions, please ask away. I sailed on NCL Star. Sneakers were a must to pack. I wore them in port and around the ship. I changed into dress shoes for dinner.
Pack a sweater/sweat shirt for the theraters the A/C is freezing and I am typically never cold.
Make sure to have a rain coat packed, just a light weight one. Dress in layers while in port