For clairfication, there are humpbacks that do winter in Alaska, migration actually happens later than October, as stated above, in fact Sitka has been holding their annual Whale Fest for many years, always first weekend in November. Through about the second/third week of May, you can also see the migration if you take a round trip Seattle cruise. Also for clarification, Belugas are NOT common to see, in fact overall pretty rare in Turnagain Arm. They can be anywhere in the Cook Inlet, and no way to predict where they will be from year to year.
Orcas are also rare on the inside passage, these are transients, which have a huge range. Pure chance to see them. A better chance for sightings from a cruiseship is southbound Inside Vancouver Island, and a ship that detours by Robson Bight, HAL, Carnival, sometimes Princess does. You again, might get lucky if you are up very early, 1/2 hour before dawn on the northbound.
I have had excellent sightings from a cruiseship- to increase your chances, a good pair of wide angle binoculars are necessary. Forward viewing is also necessary, so to track them from ahead. Proper attire absolutely is needed. A large amount of invested time, and knowing the areas will increase sightings. IF you happen to be on a ship with a naturalist, use them and inquire where the sightings were the week before. Many times, you can get time estimates from the bridge on potential areas, but you have to know them to ask. You can't just request, "when are you going through a whale area"
I have been whale watching for over 20 years and on well over 100 tours. I always spend most of my sailing time out on deck, but you will also always see me on whale watches. Superior for extended close up viewing. From a cruiseship, you have to be happy with perhaps 2 minutes of viewing, with being out for hours.