I also just returned from an Alaska cruise (Coral Princess) and saw a few humpbacks from the ship. However to see them up close, take a whale watch tour out of Juneau. I'd read great reviews of Captain Larry as recommended above. However, since there were 6 of us we opted to book with Juneau Sport Charters, Bob Mothershead so we would have the boat to ourselves. The boat was the Dreamcatcher, a 28 foot Bayliner, and was $350 for a 4 hour trip. For another $25, he will pick the group up whereever you are and return you to town or the ship. On the way back to the ship, he stopped awhile at the Mendenhall glacier. In addition to seeing a number of humpbacks up close, we stopped on the way in for a great display of eagles feeding.