Any of the whale watching or glacier cruises will yield whale sightings and while not as "whale oriented", the few times I've been out halibut/salmon fishing out of Seward we saw several whales as well, plus for about the same $ came home with bags of yummy and expensive halibut. And if you time your trip right you can keep lingcod and salmon too. On a good day you can catch close to enough fish to pay for your trip if you bought that fish at the store or fishmarket.
Not a comfort cruise like the whale glacier tours though. If you are active, go fishing and see whales. If you are prone to sea sickness and want luxury and somewhere to relax out of the weather take a tour/cruise.