I get the concept, but:

• Will you have the security benefits that I think are being assumed? If your threat is human, then, yeah, being on an island is a big deal. But…if zombies don’t need to breathe, can they just walk under the sea to an island?

• Setting aside the direct issue of, say, being chomped by a zombie, one of the larger, immediate problems you face in a situation where you have infrastructure break down — which I imagine a zombie apocalypse might cause — is loss of potable water. Islands may not be the best place to go to get fresh water (though you could get salt water, and I imagine that one could use, oh, solar stills or whatever to desalinate).

  There was a point in time where US military war planners did up a zombie apocalypse plan — to have a fun theme, but the problems that a zombie apocalypse would pose aren’t terribly far off the same kind of problems that you have to solve when doing war planning. Drinking water access played a prominent role.

  https://en.wikipedia.org/wiki/CONOP_8888

  CONPLAN 8888, also known as Counter-Zombie Dominance, is a U.S. Department of Defense (DoD) Strategic Command CONOP document that describes a plan for the United States and its military to defend against zombies in a fictional military training scenario.[1][2][3][4][5][6]

  https://www.stratcom.mil/Portals/8/Documents/FOIA/CONPLAN_8888-11.pdf

  ii . (U) The following environmental factors apply to humans in this plan:

  I. (U) Rain will be vitally important to human survival. If civil water supplies are cut off, humans will have to rely on other means to obtain water. Ground water from streams and rivers will be unreliable since it will be difficult to determine if ground water is a vector for zombie infection.

  b. (U) Operational COG #2: Potable water sources (PWS)

  i. (U) Zombies do not drink water, but humans do. Humans typically cannot survive longer than 10 days without fresh water. Zombies will likely be drawn to potable water sources by the presence of human food sources that zombies prey on . Zombies can be expected to contaminate potable water sources with various contaminants during these attacks further limiting the supply of available potable water for humans.

  iv. (U) CR #4-Safe food, water, and fuel distribution network: Ultimately, healthy human populations and the forces protecting them will require the means to acquire, purify, and distribute foodstuffs , water and fuels for heat and machine operations. Failure to maintain security supporting the distribution networks and nodes for food, water and fuel will compromise the longevity of healthy humans; decrease the amount of time that humans can remain sheltered in place or barricaded from zombie threats and could cause competition for resources that will undermine law and order. If compromised, the capabilities in this CR could undermine all the CCs in this plan.