Rankin and 28 Fathom Banks

Color bathymetric map of sea floor around East Flower Garden Bank MacNeil Bank, Rankin Bank and 28 Fathom Bank showing the connecting ridges between formations
Structural connections on the sea floor between East Flower Garden, MacNeil, Rankin and 28 Fathom Banks

Bottom Depth Range: 165-570 feet (50-174 meters)

The prominent areas of Rankin, 28 Fathom, MacNeil and East Flower Garden Banks are located around the semicircular rim of a depression in the sea floor about 14 km (8.7 mi) across. Rankin and 28 Fathom Banks are located approximately 15 km (9.3 mi) east of East Flower Garden Bank in water depths of 100-120 m (328-394 ft), and separated by a 1000 m (3280 ft) wide trough, reaching down about 154 m (570 ft).

Color bathymetric map of Rankin and 28 Fathom Banks
Rankin and 28 Fathom Banks are separated by a wide trench in the sea floor

Rankin Bank, to the north, encompasses an area of approximately 1.2 km2 (.74 mi2). The top of the bank sits about 50 m (164 ft) underwater.  Pinnacles occur around the western base of the bank in water depths greater than 110 m (361 ft), whereas hard grounds occur just beyond the eastern and southeastern flank in water depths greater than 80 m (262 ft).

Rankin Bank is named after John L. Rankin of the Minerals Management Service (now BOEM).

28 Fathom Bank, to the south, is 2.4 km (1.5 mi) long and about 0.8 km (.5 mi) wide, and encompasses an area of about 1.8 km2 (1.1 mi2).  The top of the bank is very smooth but gradually gives way to pinnacles that occur in water depths greater than 77 m (253 ft) immediately to the south.

28 Fathom Bank is named simply for its depth.

Rankin and 28 Fathom Banks are part of a Habitat Area of Particular Concern (HAPC) that also encompasses Bright Bank, and the extensive patch reefs in between the features.

These reefs consist of black corals, gorgonians, algae, sponges, stony corals and a variety of invertebrates. Mud volcanoes occur in several locations.

A school of purple fish swimming up and over a dome-shaped rocky formation
A school of fish swarms over a rocky outcrop at Rankin Bank
Reddish-purple coralline algae encrusted on rocky outcrops on the sea floor
Colorful coralline algae at 28 Fathom Bank
A field of corkscrew shaped whip corals on a muddy bottom. Three groupers swim above the corals.
Groupers swim above a field of whip corals at 28 Fathom Bank