Reef
Australia's marine wonder
A reef is a ridge of rock, coral, or sand lying at or near the surface of a body of water.
Coral reefs are underwater ecosystems built by colonies of tiny organisms.
Ships that run aground on a reef face serious damage.
To reef a sail is to reduce its area by folding or rolling part of it—a nautical practice for managing wind.
Obstruction preventing passage
- atollRing-shaped reef island
- polypFleshy membrane projection
- lagoonSheltered coastal shallows
- bleachingChemical color removal
ecosystem · marine · tropical · snorkeling · diving · biodiversity · anemone · clownfish
Shallow water hazard
- hazardSource of potential harm
- shipwreckDestroyed vessel at sea
- navigationDetermining position and course
- shallowWithout much depth
grounding · chart · rocky · sandbar · lighthouse · channel · submerged · hull
barrier
Obstruction preventing passage
bleaching · ecosystem · marine · tropical · snorkeling · diving · biodiversity · anemone · clownfish · fringing
shoal
Shallow water hazard
- hazardSource of potential harm
- shipwreckDestroyed vessel at sea
- navigationDetermining position and course
shallow · grounding · chart · rocky · sandbar · lighthouse · channel · submerged · hull · aground
square
Rhombus with right angles
line · sailor · secure · binding · flat · halyard · rigging · nautical · splice · hitch
furling
Rolling up sails
- reducingMaking less or smaller
- canvasHeavy woven cloth
- shorteningReducing length or duration
storm · wind · mainsail · points · tuck · gale · nautical · jib · halyard · boom
- Action Sports BrandsQuiksilver, Billabong, O'Neill, Volcom, Roxy
- South African PlacesJohannesburg, Cape Town, Pretoria, Durban, Soweto
Reefdeep water
Significantly submerged aquatic zone
open water · shipping lane · fairway · navigable waters · the deep
- 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