An apartment or travel trailer is a far cry from a small sailer.....there is no where to go when you get cabin fever.
Another reason to pick somewhere within a day of a remote island or group. Depending on how far off the grid one needs to be, the Maldives are full of both inhabited and uninhabited islands, and some of the uninhabited ones don't see a huge amount of traffic. Plus the climate there is nice. If one is truly insane and/or impervious to awful weather, there's always Bouvet or the Antipodes.
Unless you're really hiding from a worldwide manhunt, of course, there's always a good chance that some inhabited island would adopt you for whatever reason, and true hiding wouldn't be necessary most of the time anyway; it's not like every random cargo ship is going to check out your boat as long as you manage to look like you're wherever you are intentionally. Don't look lost or derelict and they'll figure you're just another eccentric sailor taking his toy to some remote place for fun.