Ocean Blue Holes - Andros Island Bahamas
All the main islands of the Bahamas have blue holes, but those of Andros are some of the best known. Andros has at least 178 on land as well as at least 50 in the sea.
Blue holes can best be described as entrances to the intricate cave systems which run underneath the island and sea floor. Because the ocean blue holes are connected to those inland they are affected by the tides. The ocean blue holes will "blow" and "suck" making it necessary to dive them at certain times. The "blow" usually pumps out cold subterranean water which may be milky with hydrogen sulfide and algae or, during the "suck," the water will be crystal clear as it sucks in the surrounding sea water. These different conditions create very different ways for us to enjoy the blue holes while diving.
From the incredible geological formations to the unique marine life which live in the caves, the ocean blue holes offer us some of the best diving experiences in the world.