We used Carlin Air (and can recommend highly) to take a floatplane ride to Anan Creek where we got two hours to watch bears bald eagles fishing. We saw probably 12 black bears--one mom with newly born cubs--and four grizzly bears. The plane rides as almost as much fun as the wildlife viewing!!
Icy Strait itself is not much to write home about--but the whale watching tour we booked with Captain Dan in town was spectacular. His boats only take on six passengers max--so there is plenty of room for viewing. We watched a pod of humpbacks bubble feeding over and over and over.
Seward was really beautiful--we toured the Alaska Sealife Center and took the cruise on Resurrection Bay to Fox Island for lunch. Cruise was interesting--but the ship was loaded with at least 100 people--all trying to photograph the same wildlife at the same time. To do it again, I would book a private cruise.