Blue Hole Snorkel

The Great Blue Hole is a large underwater sinkhole measuring 1000 feet around with a depth of 480 feet located near the centre of Lighthouse Reef a small atoll 100 kilometres (62 mi) from the mainland of Belize City. The hole is circular in shape and it was formed during several episodes of Quaternary glaciation when sea levels were much lower. Blue holes formed during past ice ages 65 Millions years ago when the sea level was as much as 100–120 meters lower than at present. According to Geologists and scholars these holes were formed by deeper groundwater gradually dissolving the limestone until the ceiling of these voids collapsed. Later the sea level rose and filled the holes with water.