blue hole
Submerged marine sinkhole
A blue hole is a deep underwater sinkhole or cave, typically found in shallow coastal waters.
The name comes from the striking dark blue appearance when viewed from above—the depth creates a dramatic contrast with surrounding turquoise shallows.
Blue holes formed during ice ages when sea levels were lower, leaving limestone caves that later flooded.
Divers explored the blue hole off the coast of Belize.
Eroded soluble rock terrain
- limestoneCarbonate sedimentary rock
- sinkholeUnderground collapse crater
- caveUnderground hollow in rock
- cenoteLimestone sinkhole revealing groundwater
stalactite · stalagmite · subterranean · speleology · grotto · erosion · formation · fissure
Lowest or innermost regions
- abyssImmeasurably profound depth
- unknownNot yet discovered
- bottomlessHaving no base
- darknessTotal absence of light
unexplored · eerie · haunting · legends · disappearances · unfathomable · void · ancient
Portable underwater breathing gear
- cenoteLimestone sinkhole revealing groundwater
- underwaterBelow the surface
- freedivingUnderwater diving without tanks
- decompressionReduction of pressure
wetsuit · fins · buoyancy · regulator · tank · mask · depth · nitrox
karst
Eroded soluble rock terrain
- limestoneCarbonate sedimentary rock
- sinkholeUnderground collapse crater
- caveUnderground hollow in rock
cenote · stalactite · stalagmite · subterranean · speleology · grotto · erosion · formation · fissure · sediment
depths
Lowest or innermost regions
- abyssImmeasurably profound depth
- unknownNot yet discovered
- bottomlessHaving no base
darkness · unexplored · eerie · haunting · legends · disappearances · unfathomable · void · ancient · primordial
scuba
Portable underwater breathing gear
- cenoteLimestone sinkhole revealing groundwater
- underwaterBelow the surface
- freedivingUnderwater diving without tanks
decompression · wetsuit · fins · buoyancy · regulator · tank · mask · depth · nitrox · descent
coral
Marine skeletal formation
- reefUnderwater rock or coral formation
- sharkCartilaginous marine predator
- fishGilled aquatic vertebrate
turtle · barracuda · ecosystem · saltwater · biodiversity · habitat · grouper · snapper · sponge · anemone
Belize
Central American coastal nation
- underwaterunderwater, submerged, immersed, sea bed, seabed
- cavescave, cavern, caves, caverns, grotto
- natural wondersnorthern lights, aurora borealis, auroras, rainbows, Great Barrier Reef
- underwater placesunderwater cave, underwater canyon, underwater tunnel, ocean floor, seabed
- Swimming Watersswimming beach, natural pool, lagoons, tidal pool, tidal pools
- scuba divingscuba, regulator, BCD, scuba diving, wetsuit
blue holeseamount
Submerged volcanic elevation
coral reef · atoll · underwater volcano · mountain · barrier reef
blue, hole, blues, bluer, bluest, bluish, blueness, holes, holed