Thatch Cay is a small, uninhabited 230 acre (931,000 m²) island one-half mile (0.8 kilometres) off the northeastern coast of Saint Thomas.

It is not known exactly when the family relinquished ownership of the island but it is thought to be around the time of purchase of almost the whole chain by the U.S. Government in 1917.

The cay has also historically been known for the Panulirus argus lobsters which are found around the island in large numbers.

With only 6 planned estates, McIntyre's private, highly eco-friendly design for Thatch Cay included solar powered island-wide wireless networks hubbed in the "lodge" to offer residents both family holiday and corporate use.

In 2003 McIntyre turned over the project to a San Diego firm which started selling the island.