Here is a bit of trivia about
Castaway Cay from Wikipedia..............
The Gorda Cay was once used as a stop for drug runners. The runway on the island was a true operational runway at one point, but since has been used as part of Disney's theme and is no longer functional. Gorda Cay was also used for filming in the past, the beach where Tom Hanks first encounters the naked Daryl Hannah in Splash is on the island.
Disney is said to have spent $25,000,000 to develop and outfit the island, topping the $16 million spent by Holland America on Half Moon Cay, and the lesser efforts of other companies. As a result Castaway Cay has the most extensive facilities. Sea water is changed into pure water with reverse osmosis water processors. Construction took 18 months and included dredging 50,000 truckloads of sand from the depths of the Atlantic Ocean. The island is still largely undeveloped: only 55 of the 1,000 acres (4.0 km²) are being used. Due to the island's expansive insect population, Disney cruises generally depart the island before sunset.
The pier and its approaches were constructed specifically for the Disney ships, so that they could dock alongside easily, thus removing the need for tenders to get the passengers ashore. To create the mooring site for the ships, workers dredged sand from a 1,700-foot (520 m) channel about 35 feet (11 m) deep and ranging from 200 to 400 feet (120 m) wide. The dredge material was used to build the landing island