In reply to The Ice Doctor:
Apparently, unlike cars, boats hold their value quite well (this has been relayed to me by several boat/yacht owners, so it must be true...). Now that we're at the ppm for CO2 tipping point (a line politicians seem happy to cross), the boat will be useful for accommodation in higher sea level conditions. In case of nuclear war, could be useful for a quick getaway, as long as not moored at ground zero.
I agree with abseil's point about property value. Long term diversifications, when renewed threat of imminent thermonuclear destruction is passed: AirBnB, cafe, social housing for the elderly or recent graduates...
Cyanide pill - depends on street value and how bad things might get.
Machine gun - only useful with the additional overheads (ammo). See comments above related to street value, etc.
Bribe - depends to whom and for what.