Cruising itself requires certain attire at certain times, and cruising to Alaska is no different. Even though you have most likely flown to your embarkation point, take a few hours to get the essentials at a local drugstore that you were not able to pack. It will be much cheaper than getting them on board, and you will be able to get exactly what you want.
Do not forget your still camera, video camera, battery chargers and extra memory. There is a lot to photograph, and you don't want to be caught with a great set of equipment and no media until you get to port. If you are so inclined, bring your laptop and an external hard drive to download your photos every night. You definitely don't want to take any chances at losing these memories.
It is summer, and there is a pool on board most ships, so go ahead and bring your bathing suit in addition to shorts and/or skirts. There will also be a formal night, so bring at least one semi formal or formal outfit. Other basic items for an Alaskan cruise should be good walking shoes, comfortable clothing, a shade hat and a good pair of sunglasses. Remember that it stays light almost 18 hours a day in the inside passage.
If you are planning on doing any excursions to see bears, don't forget hiking boots and a pair of jeans.
As warm as it can be on the way there or back, when you get to the glaciers, you'll be glad you packed a heavy coat, gloves, scarf and beanie-style hat. The ships provide blankets, but you are not going to want to stay seated for long, as the scenery is magnificent.
If you are sensitive to cold weather, bring your vitamins and possibly even cold medication, as you will be switching between the cold and warm temperatures frequently.
