Intermediate The Bahamas
Grand Bahama
An extensive submerged cave system beneath a flat island, and tiger sharks at the western tip
Beneath this flat, apparently unremarkable island lie kilometres of flooded galleries, carved out when the sea was much lower. And at the western tip, over a sandbank just a few metres deep, tiger sharks gather in winter.
In this guide you'll find the three things that set this island apart: an extensive submerged cave system, a tiger shark meeting point, and simple reef and wreck diving, plus when to go and what each demands.
This is where it's clearest that the Bahamas are not just reef: the same carbonate platform that forms the banks holds beneath it a record of what the sea was like thousands of years ago.
Geography and access
Grand Bahama is a flat, elongated island in the north of the archipelago, very close to the Florida coast and the path of the Gulf Stream.
Like the whole archipelago, it is carbonate: rock formed from the accumulation of calcareous remains, easily dissolved by water.
During glacial periods sea level was tens of metres below its current level, and rainwater carved out galleries within that rock. As the sea rose, they were flooded.
The result is an extensive submerged cave system, with inland entrances and a connection to the sea.
At the western tip, the shallow sandbank at low depth is the setting for tiger shark encounters, over a light bottom and with very good light.
Access is by international flight to the island, or a short flight from other islands in the archipelago and from Florida.
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