deep sea
Far beneath waves
The deep sea is the ocean below about 200 meters, where sunlight cannot penetrate.
It describes both the region and things associated with it: deep-sea fishing, deep-sea creatures, deep-sea exploration.
The deep sea remains one of Earth's least explored environments, home to bizarre life forms adapted to extreme pressure and darkness.
Extremely deep, unmeasurable
- benthicOf the sea bottom
- mesopelagicMid-depth ocean layer
- aphoticReceiving no light
- pelagicOf the open sea
ocean floor · fathoms · abyss · trench · pressure · cold · darkness · anoxic
Not yet discovered
- unexploredNot yet investigated
- fathomlessImmeasurably deep or obscure
- leviathanEnormous creature or entity
- krakenGiant squid of legend
secrets · enigma · void · silent · darkness · uncharted · hidden · undiscovered
Bioluminescent deep-sea predator
- viperfishBioluminescent deep-sea predator
- dragonfishFanged deep-sea fish
- giant squidLargest known invertebrate
- blobfishGelatinous deep-sea fish
oarfish · coelacanth · fangtooth · lanternfish · hagfish · giant isopod · tube worms · nautilus
Underwater exploration vehicle
- bathyscapheSelf-propelled deep-diving craft
- ROVPiloted-from-above underwater craft
- sonarUnderwater detection by echoes
- divingEntering water deliberately
oceanography · expedition · research · bathysphere · pressure suit · underwater · mapping · survey
Hot water underground
- chemosynthesisEnergy from chemical reactions
- extremophileLife in harsh conditions
- tube wormsSessile marine invertebrates in casings
- mineral depositsNatural rock-bound resources
sulfide · methane · ecosystem · bacteria · archaea · mid-ocean ridge
Steady, soft light
- light-emittingProducing visible radiation
- chemiluminescenceLight from molecular reactions
- fluorescenceLight emitted after absorption
- phosphorescenceHeatless delayed light emission
lure · countershading · warning signal · communication · camouflage
abyssal
Extremely deep, unmeasurable
- benthicOf the sea bottom
- mesopelagicMid-depth ocean layer
- aphoticReceiving no light
pelagic · ocean floor · fathoms · abyss · trench · pressure · cold · darkness · anoxic · sediment
unknown
Not yet discovered
- unexploredNot yet investigated
- fathomlessImmeasurably deep or obscure
- leviathanEnormous creature or entity
kraken · secrets · enigma · void · silent · darkness · uncharted · hidden · undiscovered · alien
anglerfish
Bioluminescent deep-sea predator
- viperfishBioluminescent deep-sea predator
- dragonfishFanged deep-sea fish
- giant squidLargest known invertebrate
blobfish · oarfish · coelacanth · fangtooth · lanternfish · hagfish · giant isopod · tube worms · nautilus
submersible
Underwater exploration vehicle
- bathyscapheSelf-propelled deep-diving craft
- ROVPiloted-from-above underwater craft
- sonarUnderwater detection by echoes
diving · oceanography · expedition · research · bathysphere · pressure suit · underwater · mapping · survey · marine biology
hydrothermal
Hot water underground
- chemosynthesisEnergy from chemical reactions
- extremophileLife in harsh conditions
- tube wormsSessile marine invertebrates in casings
mineral deposits · sulfide · methane · ecosystem · bacteria · archaea · mid-ocean ridge
glow
Steady, soft light
- light-emittingProducing visible radiation
- chemiluminescenceLight from molecular reactions
- fluorescenceLight emitted after absorption
phosphorescence · lure · countershading · warning signal · communication · camouflage
- watersoceans, lakes, rivers, streams, ponds
- oceansAtlantic Ocean, Pacific Ocean, Indian Ocean, Arctic Ocean, Southern Ocean
- fish habitatsriver, stream, ocean, creek, lake
- ocean depthsshallow, abyss, surface, ocean floor, shallows
- underwater placesunderwater cave, underwater canyon, underwater tunnel, ocean floor, reef
- unexplored placesunmapped, undiscovered, uncharted, cave systems, unexplored territory
deep seasurface
Outermost boundary layer
shallow water · surface waters · shallows · sea surface · shoal
deep, sea, depth, deeply, seashore, depths, seas, seawater, deepest