Here is their web site www.alaskawhalewatching.com Their tours are pretty close to the same price as from the ships. I think their was $1 difference between Princess and Capt. Larry. The trip is a total of around 3 hours. A half hour of that is getting to and from the boat so the actual whale watch is about 2 1/2 hours give or take a few minutes. This is about the same as from the ships. You meet right in Juneau across the street from the tram station right by the ships. You can book with them online or call their toll free number and talk with them direct, keep in mind any time difference.
We did them from the ship our first times to Alaska but have done them with Capt Larry every time since, which is quite a few times because Alaska is where we cruise and even though the price is in the price range of the ships we felt that Capt. Larry did a much better job. As I said the naturalists use him for best results.
When you see the whales regardless of if it is from the ships tours or from Capt. Larry you will be thrilled.