We did the Grinnel Glacier Boat Tour and Hike with a ranger. The boat ride basically takes a couple of miles off the hike, but it's still an all day, 8 mile hike. If you have time for this, I highly recommend it. We would never be able to do this on our own, but with a group, and the ranger taking frequent breaks and explaining everything, it was wonderful. The boat ride itself was peaceful. If you haven't already, look up the programs on nps.gov
