A live-aboard sailboat or motor cruiser is another frequently touted retreat option. Unless you are an experienced blue water yachtsman with many years of experience, then I cannot recommend “sea mobile” retreating. I only know a few yachtsmen with this level of experience–most notably Mark Laughlin and Matthew Bracken . (BTW, Some of the characters and descriptions in Matt Bracken’s recent novel “Enemies Foreign and Domestic”  shed some light on sea-mobile retreating.) IMHO, for a long term Crunch  with anticipated fuel shortages, only a sailboat with an auxiliary engine makes sense. If you do choose this route, then by all means select the largest sailboat you can afford (and that can be manned by a small crew) with the following features:
A minimal radar cross section.
A retractable keel so that you can navigate shallows.
A very quiet auxiliary engine.
The largest fuel and fresh water tanks possible.
A full suite of communications gear (marine band, 2 Meter , CB , and HF .)
At least two Global Positioning System (GPS) receivers, plus a sextant in case the GPS satellites ever fail. (Or in case the GPS constellation is destroyed or significantly degraded by anti-satellite (ASAT) weapons.)
A hull and rigging design that will “blend in” with the crowd of seasonal yachtsmen.
Plenty of spare parts.
Be forewarned that your inevitable desire to add a large photovoltaic array will be in direct opposition to blending in. If you buy photovoltaic (PV) panels, buy canvas covers to make them less obvious when sailing near shore. A sailboat moored at night is vulnerable to sea-going looters. Even today, piracy is a problem, particularly in the Caribbean and the waters around Southeast Asia. This threat will surely expand by an order of magnitude WTSHTF . So plan your landfalls carefully!
Mobile approaches to retreating have too many drawbacks to recommend them, except perhaps in a few cases for someone with a huge budget. Pragmatically, you will need a defensible fixed location with a deep larder , tools, weapons, barter goods, and friends that you can count on. In essence, the only tenable “mobile” approach is for the very short term: a reliable vehicle that gets you to a well provisioned and defendable fixed retreat. (But I highly recommend living at you retreat year round, if at all possible. I will articulate this fully in future posts.)