DAHAR - meaning the 'back'. A straight line of reef ending in a sheer drop.
SHARM - meaning 'crack' or 'cut'. A V shaped opening of a reef table with the widest part pointing into the sea.
MARSA - meaning a 'resting place' a 'shelter'. Often a sandy bay gently sloping down to the sea. Usually an anchoring place for boats.
RAS - meaning a 'head' or a 'cape'.
BIR - meaning a 'well'. A BIR is a deep vertical pool leading out to sea. BIRS make exceptional diving places as there is no current and the clarity when viewing marine life is exceptional.