Nosy Tanikely is a small uninhabited island a few kilometres south of Nosy Be that has been a strict marine reserve since 1968. The coral on its sheltered north shore is among the best you can see this side of Madagascar — turtles, parrotfish, butterflyfish and the occasional reef shark. The water is shallow and clear and the snorkelling is suitable for beginners.
A short walk up to the lighthouse gives views back to Nosy Be and across to the mainland. There is a small entry fee that funds reef protection; bring your own mask if you can — rentals are basic. Day-trip boats from Nosy Be combine it with Nosy Komba for the classic two-island excursion.