elanya

Big up his ego - this island, the Bahamas and his land in particular could be uber important (not marginal!)

From the point of view of one who works a lot with academics and researchers - you might be best not including ever detail of your project at this stage. A letter of introduction explaining that you're hoping to do some investigatory excavations in Harbour Island in 2009 and are very interested in their (historically important!) land would be more likely to open a dialogue than something that's spelt out in loads of detail. If they're not historically minded then this information overload could be a turn-off. Also don't mention other land owners - they're more likely to say no if they reckon you can go elsewhere to get your results.

Once they've established communications, you can go into more detail about practicalities and proposals. This would be my communications strategy!