I did shore diving in Juneau Alaska a few years ago. I called ahead and arranged for a DM from Channel Divers to go with us. Viz was good, 20-50 feet according to my log book. Saw a lot of sea life, went face to face with a sea lion, huge octopus, the fish are are either brown or gray, no colorful fish like in the Carib. Very different from anything I was accustom to. I was told it would take a couple of hours to go out to a wreck. Since there was only 2 of us diving the cost was way to expensive to charter a boat. Even though Juneau has moderate temps, the water is cold but not as cold as Lake Michigan at the end of summer. I would recomend a dry suit. I have read about diving in Anchorage, I'm sure it is a lot colder but would like to try it some day.