Welcome to cruise-chat.
The thing with whale watching is that there are no guarantees, whether you are on the ship or on a tour. It is pretty much a matter of luck. We went on an Alaska cruise last June. We saw a few whales on the tour we took, including humpbacks, but don't expect to see epic leaps from the ocean like you see on TV. The whales we saw just glided at the surface for a few seconds to take in air and then they'd submerge. We wouldn't have known they were whales if the guide didn't tell us they were. We did see one humpback tail come out of the water as it submerged. The guide said this meant it was diving deep and would be submerged for a while. Pretty much a ho-hum tour. This was in Prince Rupert.
There were a couple sightings from the cruise ship, but by the time you could react they were gone.