I dove the Seychelles. Due to El Nino the water temperature rose and bleached the coral. It now looks like the seabed has been dynamited. The fish are still around though: great variety, colours and also snorkelled above a whale shark! Turtles and dolphins too! On Mahe I recommend Dive Seychelles at the Mahe Beach Hotel. Run by 2 S Africans with a Scandinavian DM as well as local DM and Boat skipper. It is the most professional outfit on the island.
The real bonus is that the Seychelles are a dream destination, beautiful uncrowded idyllic beaches, a friendly local population, excellent weather just the most beautiful place in the world for 2-3 weeks.