I think we, as humans, tend to be typically disconnected with nature. Being outside, even in short bursts can re-establish that connection at least briefly. It can let us know that we're more than just a sum of social obligations and chores. That life is more than just the pervasive technology present in our lives. It can also create a sense of awe and humbleness unmatched by other activities.

I've thought about kayaking more before too, I've done it a few times and it can be a good bit of fun, plus it ends up being good exercise whether you want to or not. Most every time my arms become significantly sore after trying it out. I recently bought a cheap groupon to try Kayaking around here. Maybe you should see if anything similar is available around your area.