I dived in the Seychelles last year, great diving, surprisingly healthy coral fields (I read everywhere that a huuge bleaching killed everything there - simply not true...), turtles, a few sharks. Nothing spectacular, such as whaleshark & Co. Btw the Seychelles is also great topside, we cycled around La Digue (which Island I'd recommend the most). I can't recall the name of the dive Op on La Digue, but You'll find them near the Jetty, its a small place. We also stayed a week on Praslin, where I dived with Octopus - also a well-run establishment. The dive I'd call the best was with Octopus at Shark Rock: 30+m visibility, dozens of eagle rays, a nurse shark, nice granite and coral formations.
Next year I'd like to try something new. Addicted to coral and nice colors, I am eyeing Mozambique but a little worried about topside safety in mainland Africa. Especially that I like to combine diving with land-excursions, night time stargazing, etc - which is not a life insurance down there, but I am still collecting information.
