There are some spectacular sights from the boat ride. But be sure to take anti-nausea medicine if you have motion sickness. The boat ride is stop and go for whale sightings, animals (seals, sealions, otters, eagles, foxes, etc), and glaciers.
If you do get sick, sit in the back of the boat. The staff will give you vomit bags, ginger ale and saltine crackers.
First of all the northern Pacific isn't exactly a warm body of water. But get in close to a glacier and feel the wind screaming on by after it has crossed a hundred mile wide ice field--now that is cold. I didn't exactly anticipate how cold it could be close in to a glacier and I was not wearing appropriate clothing. It took a hot shower and an hour nap under a thick quilt before I once again felt reasonably warm.
Because the fjord is exposed to the sea breeze, the weather can be freezing cold so get ready your warm clothings. Sometimes storm can happen and it is advisable not to go out to the fjord in stormy weather.