2021 Map of Marquesas Keys West

About this map

The Marquesas Keys and the shifting seafloor of the Florida Straits define this maritime landscape at the western edge of the Florida Keys. This area is dominated by submerged features and shallow banks, most notably the expansive area known as The Quicksands and Halfmoon Shoal. These underwater hazards are critical for navigating the transition between the Gulf of Mexico and the Atlantic Ocean, separated by the deep Rebecca Shoal Channel. Tiny outcroppings such as Mooney Harbor Key and the Gull Keys provide the only terrestrial anchor points in a region otherwise characterized by shoals like New Ground and Isaac Shoal. The spatial arrangement of these features illustrates the complex hydrography of the Straits of Florida, where navigation has long relied on precisely identifying these subtle changes in depth and seafloor composition.