As mentioned, orcas are NOT usually seen with Alaska cruisers. With some round trip Seattle cruises they do port in Victoria, and orca whale watches are available there. HOWEVER, these tours are an hour shorter than the regular tours. Which means the southern resident pods have to be within range, and it's a large area. The tour operator will know, if you are going to see them or not before you go, but this is too late to cancel for a a refund. When I go to Victoria, I always go out at least twice to hedge my bets. I have also spent several days on the northern end of Vancouver Island in Port Hardy and Telegraph cove with tours of the northern residents. I went out on 4 trips the last time.
If you are sailing inside Vancouver Island, you can have a chance of seeing orcas. I have several times, BUT it takes time invested out on a forward viewing area with a good pair of WIDE angle binoculars. It helps to know the area, which may be difficult from a cruise ship, but I request information from the bridge. Carnival, HAL and Princess, at times, will detour to Robson Bight, which is an orca hot spot on southbound transits.
I am always up at least 1/2 prior to the posted dawn time on the northbound transit. Have seen orcas a couple times in that timeframe too.
Out of Juneau, you have a very slim chance of orcas, but 100% chance of humpbacks, same with whale watch tours out of Hoonah. Another, iffy chance of orcas out of Seward, but again, multiple trips will hedge the chance.