I recently had an exchange with a man on twitter that said his solution to being a prepper was that he bought a boat and was living full time on it. Off the grid. I guess that is a different take on why to buy a boat.
Living on the boat has been my fall-back position for some time. If things go south I can retreat to the boat and live there. If that happens I do need to get it hauled from my current water because I'm land-locked for the next few years.
Regarding boating and the economy, that is absolutely true. As gas prices have gone up the number of boaters has gone down. On one hand, I hate paying so much for gas, but on the other, I like the water better when it's less crowded. We have two boats, a 22 and 50 footer. The big one uses a lot more fuel, but can also be enjoyed thoroughly in the slip. Of course, my marina is a lot like a state park, and not just 4000' of dock with a parking lot. If only the water didn't freeze it would be perfect.