Answer:

reef

Answer	Crossword Clue
REEF	Great Barrier ..
REEF	Coral structure
REEF	Ship's bane

REEF	Coral ridge
REEF	Great Barrier ....
REEF	Sailors' hazard
REEF	Coral formation
REEF	Mariner's danger
REEF	Undoing of the Hesperus
REEF	Ship wrecker
REEF	Shipwreck cause

REEF	Shipwreck site
REEF	Scuba setting
REEF	Boater's hazard
REEF	Diver's milieu
REEF	Keel scraper
REEF	Shallow sea feature
REEF	Snorkeling locale
REEF	Key, e.g.

REEF	Sailing danger
REEF	Atoll barrier
REEF	Ocean danger
REEF	Sailor's concern
REEF	Sea hazard
REEF	Water hazard
REEF	Ocean hazard
REEF	Snorkeling site

REEF	Submerged hazard
REEF	Shipping hazard
REEF	It might be just below the surface
REEF	Wreck site
REEF	Diver's haunt
REEF	Yachting hazard
REEF	Biodiverse habitat
REEF	Diver's domain

REEF	Pilot's hazard
REEF	Snorkeling spot
REEF	Great Barrier ...
REEF	Boat bottom basher
REEF	Coral habitat