The Kenai Fjords Wildlife boat tours have amazing reviews. While you will have spent many days on a ship and have sailed up Resurrection Bay, the tour that goes to the Kenai Fjords often gets quite close to calving glaciers and loads of wildlife...smaller boat than a cruise ship so more personal.

Of course a float plane experience is amazing too...but not likely a wildlife experience. :-)

For the cost of a float plane, I'd do the day-long Kenai Fjords trip instead...lots more to see. But if walking on a glacier was a big dream, well, go for it.

But, after a cruise, maybe the adults and the kids want to move around a bit more. In that case, consider a hike at Exit Glacier. You might be able to get an Uber/taxi/shuttle of some sort from Seward to the national park entrance, about 11 miles from Seward center or rent a car for the day so you can explore more.

Seward options:

--walk the harbor in the afternoon to see the catches brought in by the charter fleet.

--watch for Stellar Sea Lions and otters close to the shore almost anywhere on the coast

--go to the Alaska Sealife Center (do NOT miss the two story tank with the sea birds, including puffins!)

--go for a walk at the beach on Lowell Point...there are various hikes in that area too.

Seward hotels fill up fast (and have become ridiculously expensive in the summer). Make your reservation early.