Bermuda Coral Reefs
The Basilica and Cathedral

Both Basilica and the Cathedral coral reefs in Bermuda are located quite close to the opening of Castle Harbor, Bermuda's original port entrance. 
The Cathedral is a series of breaker reefs that have created a number of vast caves, overhangs and canyons. The larger of these caverns looks somewhat like a Cathedral and therefore the name of this reef site. Both Basilica and the Cathedral coral reefs are popular hiding place for schools of Snapper and Margate. 
These are homes to large Tarpons as well. You can see vast schools of Parrot Fish passing this area during the spring. This is a phenomenon quite common to Bermuda, but not heard of anywhere else in the Western Hemisphere. You can expect to see in excess of 100 massive Parrotfish traveling together.  
There are many types of parrot fish. These Parrot Fishes tend to group within their own types. That means you will see groups of Midnight Blues or groups of Stoplights or even groups of Blues, but never a mixed group. 
Depths vary from the shallows of 15feet to around 55ft. For the divers, navigation through this area has always been a little difficult. It's very easy to get disoriented in the many canyons and caverns, although site actually is quite compact.  
The closest landmass to the south is Tortola in the British Virgin Isles. Watch out for the massive and very inquisitive Tarpons. These massive fishes, sometimes in excess of 5 feet, are likely to follow you wherever you go. 
This can be slightly scary, but to date I have not heard of anyone being injured by a Tarpon. Usually they are quite harmless and friendly. However they are generally quite inquisitive by their very nature and keep following you. 
They have a typical foil wrap appearance. This is the reason why flash photography becomes difficult with them due to the reflections. However, a flashlight will always be handy to have with you. Many caves, cracks and crevices are home to Lobster and Crabs. Look out for the Spanish Slipper Lobsters in the shallow sand areas. 
Related Articles 
1) Check out Bermuda Coral Reefs to know all about the reef systems in Bermuda 
2) Check out Scuba Diving &áDive shops to know all about diving in Bermuda