We had a great morning trip with Prince of Whales for 3 hours. The naturalist was so informative, telling us everything you'd want to know about the different types of whales. She also told us about the rules around how far boats should stay away from whales not to disturb them and the skipper stuck to that (and we saw other, smaller boats disregarding the rules!). We saw many Orcas, three Humpbacks and some shy Porpoises which was so beautiful.
We had a couple of families with young children on the boat - I wouldn't recommend taking small children personally. You do have to stare into the sea for a while and look for tiny signs of whales until you then come closer to them, so kids might not have the patience for it (these ones certainly didn't...).