If you go for less than 6 hours on a boat tour from Seward, you don't leave the bay. That means your chances of seeing whales greatly diminishes. You definitely can see whales in the bay, but I have seen them much more often on the 6 hour or longer tours.

I find the time on the 6 or even 9 hour boat tours goes so fast. But then I am excited about all that you see on those tours. That is one reason why Major Marine with their buffet doesn't excite me. I bring snacks with me and eat when I want, not when they tell me to. I am outside on deck looking for whales and other wildlife for much of the trip. But as was said, everyone is different.