Double North is the reef that is north of North Dry Rocks in Key Largo Florida. The 3 mooring balls here are on the best sections of the reef that feature huge coral mounds and heads with abundant sponges and sea fans growing on them.
This is another great example of a dive site in Key Largo that is great for training because it never gets deep and there is never any current. Because it is a little closer to shore than the barrier reefs, so it also typically has less waves. Good for snorkeling and diving because the reef has enough profile to reach close to the surface and deep enough to check under all the ledges for nurse sharks and eels.