My understanding is that the various cruise lines must alternate between the various Glacier routes or they will be over-run with ships. So they each usually have a few ships or even may sometimes skip a year at some locales. Glacier Bay is probably their favorite site, then Hubbard Glacier, College fiords etc. I have been through college fiords. It's basically 3 hours of cruising, where Glacier Bay is a full day near the Glaciers. I am on the Radiance in August and we go to Hubbard Glacier. You might consider Princess Cruises. They go to Glacier Bay and College Fiords this year.