Asking this question leads to another cascade of questions:
What is yourself?
Are you your thoughts? your actions?
Where is the thought coming from? What is its root?
When I have questions like this I turn to Buddhism
Buddhism breaks beginning meditation into two parts
Samatha: Peaceful abiding
When you let the mind rest, and remove objects of attention from your mind, you are left with what the mind has in it. I think that at first your mind starts coming up with things, many things pop up, but after awhile you can let them go through you. Your mind rests and perhaps insight comes into your mind rather than just pop ups of random stuff. That is a breakthrough. These intuitive moments can be about the world, a relationship, or a thing, but they always are a way of facing yourself; you face your beliefs, your thoughts, your history, and your habits while in this mindspace.
Now does kayaking have these kinds of traits? During the kayaking experience you certainly are not rid of objects of attention, in fact you have an overdose of this kind of input. By the end of a day of kayaking your brain wants very little to do with more stimulation, and this is when kayaking allows you to face yourself, to reflect. These opportunities are magnified on multiday trips where you are in wilderness with nothing but time a few friends, empty minds, and a fire. These times are normally quiet and thoughtful times. The moonscapes inspire empty minds, the sounds of water lightly wearing away rocks sets a tone for deeper thought. We can have insight in these places, if we choose to.
There have been times when kayaking has not felt like meditation, when it has been a way to get away from myself. I did't have to deal with anyone or anything other than the river while I was out there. I let the fear and anxiety run my mind, take me away from the moment. This has changed over time though. As I get older I see it as a regenerative force in my life, as a thing that I do to find myself, to come up with a fresh direction or idea about what I should be doing with myself. It inspires me, it leads me to insight about myself and my life.
I do believe we can face ourselves through the actions of kayaking. It is a purifying thing. You let the fear and excitement of kayaking clean your mind and soul, then you have a clean slate to work from. You have a mind that is primed for thinking, it is no longer distracted, it is satisfied, saturated, sometimes overly stimulated.