Based on a tripadvisor recommendation, I booked the 26 Glacier Cruise as an afterthought when no rental cars were available. You can't get close to a glacier unless you venture out of Anchorage, and their Web site (...) made it easy to book a ride from downtown Anchorage to the Port of Whittier to board the boat.
(The site also lets you book a train to Whittier. If you choose to drive the 50 miles, make sure you understand how to negotiate the oddball Anderson Memorial Tunnel. It has a hefty toll, and a strange schedule that allows trains and two-way traffic to alternately share a single, 2 1/2 mile, rock-hewn lane through the mountain.)
The coach trip was the first of many surprises. $45 per person for a 100-mile ride is a bargain, especially when it includes entertainment. I don't know if Gary was a typical driver, but he told interesting anecdotes that made the ride seem short. Stories about avalanches. World War II trivia. Beluga whales. Why the army built the Anderson Tunnel. Why the mudflats are dangerous. Where to get the best seafood in Anchorage. He stopped at a few scenic points, and trained binoculars on white dots of sheep high in the mountains. Gary was a fascinating guide.
The 4 1/2 hour glacier tour of Prince William Sound flew by like two hours. You're assigned seating at a table/booth on one of the boat's two decks. The Klondike has walls of windows all around. Depending on your seat, you could comfortably sit and enjoy spectacular scenery without ever getting up, making it a good choice for people with physical limitations. (I don't know about wheelchair accessibility.)
They served a simple but sufficient hot lunch and provided free self-service coffee and tea. There's also an onboard food and drink bar, including cocktails, souvenirs, camera film. The bathrooms ... excuse me, "marine heads" ... are nice, and better than most restrooms in Whittier, according to Gary.
I saw people playing cards, talking, napping, but for me it was fun to move around the ship's outdoor decks to take in the incredible views. (Wear warm outer clothes.) Over the speakers, they talked about the glaciers and wildlife while scouting the waters for seals and orca. The glaciers are huge and blue and ancient and breathtaking. While watching Surprise Glacier, a chunk the size of a two-story building broke away and crashed into the sea.
Go to the 26 Glacier Web site. If the pictures make your heart race and your camera finger twitch, then you will enjoy this cruise. I wondered it would be worth $371 ($281 for two adults, $90 for two rides.) In retrospect, this spectacular experience alone was worth the time and expense to travel to Alaska.