Google Maps: "Kayak across the Pacific Ocean ... 6243km"

Trying to figure out the flight distance between Shenzhen, China and Vancouver, BC, I plugged the two cities into Google Maps (not realizing there are no flight paths there, at the time). I did not get what I wanted, but the outcome was interesting: They give me driving directions to a port, and from tell I’m supposed to “Kayak across the Pacific Ocean”, about 6243km to Hawaii, and then kayak another 4463km to Seattle, and drive up to Vancouver. Ok then, I’m right on it, see you in couple of years.

I wonder though, is the kayaking part something they are working on or part of the biking maps?