The cays are about 4 to 6 feet above the high tide point. The oldest existing map of these islands, is the one made by US Corps of engineers in 1920. The islands are known to be at least 200 years old. The islands used to be a coconut plantations and the coconut producing palms are at least 50 years old. There are phones in Bluefields, and Pearl Lagoon.
Satellite phones are another option.
We currently communicate with the cays with a VHF radio from Pearl lagoon. This year 2000 satellite phones started working from the cays. Rain water can be collected in a cistern and used for non-drinking purposes. If treated through chlorination and carbon filters, it can become drinkable. The presence of palm trees is a proof of fresh water under the cays.