barrier reef 
noun
A coral reef close and running parallel to the shore but separated from it by a channel of deep water.Reefs are generally divided into three categories; the barrier reef, the atoll, and the fringing reef....
- Closer contact reveals that sport divers who come to these clear, southern waters protected by a barrier reef, fearlessly feed the large group of stingrays which gather in this region.
- It is a 100-hectare tropical garden on the raised coral of the barrier reef surrounding the lagoon.
- watch the clock
- watch the pennies
- watch the time
- watch the world go by
- watch this space
- watchtower
- watchword
- water
- water adder
- water agrimony
- water aloe
- water antelope
- water apple
- water archer
- water arum
- water ash
- water-ask
- water-attracting
- water authority
- water baby
- water bag
- water-bailage
- water bailie
- water bailiff
- water balance