reef
Shallow underwater hazard
A reef is a ridge of rock, coral, or sand lying at or near the surface of water, often hazardous to navigation: The ship ran aground on a reef.
Coral reefs are underwater ecosystems built by colonies of tiny organisms, rich in marine life.
To reef a sail is to reduce its area by folding or rolling part of it—a way of managing strong winds.
Ring-shaped reef island
- lagoonSheltered coastal shallows
- barrierObstruction preventing passage
- fringingAdding decorative border
- caySmall coral island
key · island · shoal · shallow · tropical · Indo-Pacific · Caribbean · Red Sea
Fleshy membrane projection
- calcificationMineral hardening of tissue
- limestoneCarbonate sedimentary rock
- stonyRocky or emotionless
- branchingSplitting into separate directions
plate · massive · bleaching · tentacles · calcium carbonate · staghorn · brain coral · elkhorn
Striped reef fish, anemone symbiont
- parrotfishBeak-jawed coral-eating fish
- surgeonfishReef fish with tail blades
- grouperLarge predatory reef fish
- morayPredatory tropical eel
manta · shark · sea turtle · anemone · starfish · sea urchin · octopus · lobster
Source of potential harm
- navigationDetermining position and course
- chartData shown visually
- shoalShallow water hazard
- shallowWithout much depth
grounding · channel · passage · lighthouse · buoy · warning · rocks · submerged
Range of life forms
- habitatOrganism's natural environment
- algaePrimitive aquatic photosynthesizers
- seagrassSaltwater flowering plant
- foodwebEcosystem's feeding relationships
trophic · keystone · species · flora · fauna · phytoplankton · zooplankton · herbivore
Destroyed vessel or vehicle
- salvageRecovering damaged goods
- anchorSecures ships to seabed
- treasureValued wealth or keepsake
- cannonLarge mounted gun
ballast · foundered · grounded · wreckage · encrusted · submerged · hull · debris
Portable underwater breathing gear
- snorkelUnderwater breathing pipe
- underwaterBelow the surface
- visibilityRange of clear sight
- dive sitePlace for underwater exploration
buoyancy · wetsuit · mask · fins · freediving · night dive · dive boat · coral garden
atoll
Ring-shaped reef island
- lagoonSheltered coastal shallows
- barrierObstruction preventing passage
- fringingAdding decorative border
cay · key · island · shoal · shallow · tropical · Indo-Pacific · Caribbean · Red Sea · Mesoamerican
polyp
Fleshy membrane projection
- calcificationMineral hardening of tissue
- limestoneCarbonate sedimentary rock
- stonyRocky or emotionless
branching · plate · massive · bleaching · tentacles · calcium carbonate · staghorn · brain coral · elkhorn · fire coral
clownfish
Striped reef fish, anemone symbiont
- parrotfishBeak-jawed coral-eating fish
- surgeonfishReef fish with tail blades
- grouperLarge predatory reef fish
moray · manta · shark · sea turtle · anemone · starfish · sea urchin · octopus · lobster · barracuda
hazard
Source of potential harm
- navigationDetermining position and course
- chartData shown visually
- shoalShallow water hazard
shallow · grounding · channel · passage · lighthouse · buoy · warning · rocks · submerged · sandbar
biodiversity
Range of life forms
- habitatOrganism's natural environment
- algaePrimitive aquatic photosynthesizers
- seagrassSaltwater flowering plant
foodweb · trophic · keystone · species · flora · fauna · phytoplankton · zooplankton · herbivore · predator
wreck
Destroyed vessel or vehicle
cannon · ballast · foundered · grounded · wreckage · encrusted · submerged · hull · debris · maritime
scuba
Portable underwater breathing gear
- snorkelUnderwater breathing pipe
- underwaterBelow the surface
- visibilityRange of clear sight
dive site · buoyancy · wetsuit · mask · fins · freediving · night dive · dive boat · coral garden · drop-off
- beach/coastalbeach, shore, coast, tide, wave
- ocean lifeocean, sea, sea creatures, shark, sea life
- sea lifeshark, whale, dolphin, salmon, jellyfish
- underwaterunderwater, submerged, immersed, sea bed, seabed
- natural structuresmountain, volcano, cave, canyon, valley
- water bodiessea, lakes, lake, rivers, streams
reefabyss
Immeasurably profound depth
ocean trench · trench · deep sea · open water · ocean depths
reefopen water
Unobstructed body navigable freely
navigable waters · deep water · safe harbor · shipping lane · fairway
- coral reefCalcium carbonate marine ecosystem
- barrier reefsOffshore coral formations creating lagoons
- Great Barrier ReefVast coral formation near Australia
- coral reef protectionConserving colonial marine habitats
- artificial reefConstructed undersea ecosystem base
- tropical reefWarm-sea underwater formation
reefs, coral reef, reefer, reefed, reefing, barrier reef, artificial reef