Hi Vanessa,
Sammy's right, Atlantis Divers is one of the best centers for organization(the biggest in Brazil), and standards are very high! I own a dive center in Natal, the closest mainland city to the island of Noronha, where Atlantis Divers is located. I have to say this region of Brazil has some of the best diving around!Noronha is a federally protected island, kind of like galapagos, so getting flights there can sometimes be complicated and somewhat expensive even though worth every penny! Here in Natal we don't have the capacity for a large group, but as a PADI resort we can handle up to 8 divers equipment wise. Check out our site cajudivers.com, if you need any other recomendations on Brazil feel free to ask! We can recomend other dive centers down south if you were thinking more along those lines, however the water is just a tad colder!
cheers,
Michelle