Depends. If your ship goes to Icy Strait Point, there's whale watching thre.
Chilkoot Charters in Skagway offers what they call a wildlife tour, which includes whales. But saince they are not specifically calling it a whale watch they are not gauranteeing you'll see whales. In Juneau the vendors guarantee you'll see whales.
Becky
http://www.Alaskapersonaltours.com