The only way to view the glaciers in Glacier Bay is by boat. We took the daily boat tour that leaves Barlett Cove at 7:30am and returns at 4:00 -- in time to catch the plane back to Juneau.
Because the glaciers are about 50 miles away from Bartlett Cove, we didn't actually see the glaciers till lunch time. However, there were plenty of other things to see. A national park ranger pointed out birds and other wildlife and provided commentary and answers to our questions. Every now and then, we would spot humpback whales. And if we saw something really interesting (like bears), the captain would stop the boat to allow us time to look.
The boat will seat about 170 people but there were only 50 people when we went so we were able to spread out. Each passenger got a free travel mug to get the complementary coffee, tea and hot cocoa. Some seats were set up like dining table booths while others were laid out in rows like airplane seats. There were enough restrooms and there's an outdoor deck for viewing.
It was raining most of the day but that did not damper our enjoyment too much. The advantage of going on a small boat instead of a large cruise ship was that we could get a little closer to the glacier. This was awesome, and we parked about 45 minutes in front of the glacier before making our way back.
The lunch provided was surprisingly good -- a hot ham and cheese sandwich with fruit and cranberry juice. We were also served a wild mushroom soup that tasted like home made. And of course, beer and snacks were available for purchase during the cruise.
Most of the large cruise lines are able to cruise by night so that you could wake up already in front of the glacier, but the day cruise allowed us to explore Barlett Cove and stop on a dime for wildlife -- something that the large cruise ships cannot do.