While Sean's hacker spirit is truly admirable, I don't know how I feel about his lifestyle as a choice.
It is, of course, none of my business how he lives his life. If he's happy, great! Personally though, I no longer covet such nomadic lifestyles like I did back in my 20s. My main issue with them is lack of social opportunities and the inevitable loneliness it brings. I'm not a social butterfly by any means, but one thing I've learned about myself is that not having other people around me for extended periods has a noticeable negative effect on my mood. As such, living on a sailboat sounds like a total nightmare.
I have come to view solitude as a dessert: really nice to have after a regular meal, and maybe binge on every now and then even, but if it makes up the majority of your meals for extended periods, it'll make you sick.