As somebody wrote, Baa Atoll is very good. We have staid at Milaidhoo (excellent snorkelling) and Amilla Fushi (very good snorkelling). Milaidhoo had slightly stronger currents a couple of days, but I can't imagine you would be disappointed with the snorkelling at either.

And I slightly disagree with Pausanias: the hotels themselves do care about the reefs (after construction...). Unfortunately they have neither the money nor the scope to return the Maldives to the level of Raja Amput. But they do at least make some minimal investment in reef health and regrowth (or at least both of the places I mention did).