N.S.
We went on an Alaskan cruise in June of 2004. It was wonderful! If your in-laws are interested in seeing wildlife and don't have binoculars, those would be great. There are usually whales everywhere, as well as lots of birds. We ended up buying ours on the ship and they were not cheap. Also, as someone mentioned, most drinks cost money on cruise ships. If there is a way to buy a drink voucher in advance that might be a good idea too. I hope they have a fantastic trip. We were blessed with exceptionally good weather while there.