Beware of travel agent "cruise specialists" who tell you usually there are "lots of Orcas and whales in May cruising the Inside Passage". Usually a lie, until the tiny herring and large slamon come into the coast from the ocean, in june or july or even august!!

If seeing Orcas is your goal, check with the Alaska department of fish and game on when the herring feed fish are expected from the ocean to the coast to spawn.

DO NOT BELIEVE A "CRUISE SPECIALIST" travel agent !!
I had a dozen such lie to me in the SF Bay Area.