Reunion is a very interesting island, being a French district. It is a domestic flight for EU countries to get here, no customs.
Diving, like everywhere, is weather and season dependent
Being a volcanic island and not a coral island makes for very interesting caves and narrow channels to swim through. The water temperature was 24 degrees Celsius and the visibility about 20 m. Abundant fish life and for the observant ones, lots of small stuff. Whale talk enhanced the dive experience.