Re: I am 26, and seriously considering moving aboard with my girlfriend. Any advice?
I'd like to add another point... diesel heat.
I spend time on the boat on weekends in the winter, doing cleaning, repairs, upgrades, whatever. I find myself wishing for a diesel heater. I think if I lived aboard, I'd definitely get one. And it would be the kind that sucks in flue-warmed air through an extra tube-in-the-flue, then exhaust goes out the normal part of the flue. Then there's no moisture build-up from exhaust gasses going into the boat.
Interior heat slowly pumps moisture - from cooking, showering, breathing, etc. -- out of the boat. (The warmed air absorbes extra moisture, and as that warmed air flows out a vent or cowling, out goes the moisture.)
Being cozy and warm has a lot of value. And women seems especially fond of it.
Fun fact #2484: In my avatar, that's DavidPM at the helm of my boat.
Bland, non-political statement goes here.