Do you want a guide or not? If you're willing to go unguided you'll be able to find a ton of places that will give you a boat to hunt from when you book your lodging with them. I've hunted Kupreanof island twice this way.
First time saw quite a few bears and got a nice one, the second time only saw one and it was too far off to get to. However I had a buddy who managed to shoot a wolf. I had a great time staying in a cabin and hunting and fishing from a boat.
For a totally boat based hunt I don't have a clue.
