[Mesh] Mesh networks for remote islands?

A friend of mine is involved in a project to provide low cost weather forecasting and emergency communications in the Marshall Islands. He was asking me about various ham radio protocols like AX.25 and it occurred to me that a mesh network using WiFi radios might be a better solution that could provide general Internet access for a similar or even lower cost. The stations would need to be able to operate in remote. unattended locations with only solar power. I am thinking that each island could have one or more "central" sites with long distance links to one or two (or more) other islands, and then a local network that would be used to communicate locally on that island. I'm still gathering more info about distances and elevations of the islands, and whether line of site communications is possible. Can anyone think of reasons why this would or would not be a good way to do things? -- -steve