I plan to retire as soon as I can start collecting SS. That's 3 yrs from now, and I just hope they haven't done away with it before I get started. As far as living on $700 a month, I think if you own your own boat, don't have medical
issues that require ongoing expensive treatment, and are debt free, you should be fine. Of course, you should probably start learning
how to do without most of the luxuries we Americans think are necessities, a few years before you retire.
Otoh, if you have a wife, kids
and grand kids
that expect you to be there for them all the time...
Your cruising dreams are screwed.