What is the name of the barrier reef that is just off shore in Belize?

Most people refer to it as just the Belize Barrier Reef.

Contrary to what most guidebooks say, it is not the 2nd longest barrier reef in the world, but the 5th longest (though it may depend on how you measure reefs, and it is the longest in the both the Western and Northern hemispheres.)

--Lan Sluder