Northbound cruises usually cost less than southbound. The advantage of northbound is that your flights to the ports of Seattle or Vancouver are shorter than to Anchorage. This is also a good way to start if you would like to explore Alaska by land after your cruise. (Of course, you may explore by land before the cruise as well.)
If your cruise departs Vancouver, consider flying into Seattle and taking a train, bus or shuttle to Vancouver. There is usually a cost advantage to doing this and flights to Seattle might be more convenient.
You came all the way to Alaska, so why not extend your trip either before or after your cruise. Cruising gets you to places, Juneau, for example, that are inaccessible by road. A land tour gets you to places like Denali that aren’t accessible by water. A land-sea combination shows the best of both worlds.
An essential element of a rain forest is rain. Much of Southeast Alaska, the prime cruising area, is a rain forest. Be sure to prepare for rain. Layering is a good idea in Alaska. Pack some synthetics, umbrella and rain gear so that you don’t miss any part of Alaska due to the weather. Remember that there is no just thing as bad weather, just bad clothes.
You might not think of a cruise ship as a good place for whale watching or other wildlife viewing, but you are likely to see many of Alaska’s wildlife from the deck of the ship. Attend the ranger lectures on board and bring your binoculars.
In the early summer, Alaska has long periods of light. If you have difficulties sleeping in a light room, bring a sleep mask.
The Alaskan mosquito is the honorary state bird. Bring along insect repellent as well as sun screen.
If you depart from Vancouver, you will clear US Customs in Canada. Be sure to allow plenty of extra time at the airport.
When entering Canada, be aware that a DUI is considered a felony in Canada and you may be denied entry. Doing a round trip cruise from Seattle might be your only option for cruising in Alaska.