A recent comment said:
For kayak I’d say “usually 1-2 person” as tandem kayaks are very common. 3 person kayaks are rare but not unheard of, example Pamlico 160T has a third mini-seat for a child.
When I am traveling on the local bike trails and rivers I about see the same number of tandem bikes as I do tandem kayaks. Maybe a few more tandem kayaks, but not enough that I would say they are usual.
On the other hand in the same area, maybe half or 1/3 of the canoes I see are one person white water canoes, with the rest being 2 to 3 person canoes. I have never really counted any of these so maybe it is all personal perception.
How common are tandem kayaks?