All of the HOP ON HOP OFF tours are great for children because you can go at your own pace, take time out to regroup, spend as much or as little time as you want at the various stops. The Gold Panning experience in Alaska is super and so is the Husky Puppy Dog Sledding Camp .. yes you get to hold the little husky puppies. More suggestions??
In Boston, The hop on Hop off bus tour. It's great for kids ( of all ages)
Bermuda, the ferries to other areas of the Island. Not to long and they are exciting for kids.
Im an adult and have always wanted to go Gold Panning.
Some ships do have tours just for kids. Inquire at the shore excursion office on board or ask them for recommendations. Usually kids enjoy beach destinations.