Thomas reef is the smallest of the four reefs and famous amongst Technical divers for the canyon that begins at 35 meters and descends to 92 meters and runs parallel to the main reef. 

The dive starts on the southern tip and begins with a colourful wall, a few meters on the wall pans out into a plateau at 25 meters with a row of huge fan corals, check the fans for long nose hawkfish hiding in the branches. A whitetip reef shark can often be seen swimming on the edge of the plateau, and schools of large tuna and barracuda can also be found here.

 As the reef is small currents can be strong at the most northerly tip of the reef so tuck in close to the reef, as currents also come from the back of the reef the dive can come to a standstill very quickly or if the currents are in your favour you can swim to the back of the reef where there are overhangs and schooling black and white snappers.