They can be sneaky alright, especially if you didn't see them before their 5 to 7 minute long deep feeding dive.
I'd say it was half the whales fault. You'd think they would keep a better watch as they come up for air. I was sea kayaking up Grenville Channel (milking back eddies against the steep rocky shore) when one appeared about 20 feet ahead, coming my way, fast
I had to hit the rudder hard, lean to one side, and do a high brace paddle stroke not to get hit. You'd think it would have had an eye out for driftwood 'cause it's gotta hurt to get your blowhole smacked!
Cetacea Lab on Gil Island has been documenting whales in the entrance to Douglas Channel area for years and the numbers keep building for all species. http://www.cetacealab.org/index.php
I asked a Haisla elder what the "normal" numbers for Humpbacks in this area would be, and he said he didn't know. Apparently that knowledge has been lost in the mists of time because of how long the commercial whaling hunt went on, combined with so many people dying of smallpox.