We went to Maratua Atoll this past May. While the weather was good, we saw no Mantas, no Cudas and besides the excursions to "NO Big Fish Country", Sangalaki and Kakaban, we only dove the house reef. Diving was just ok, nothing to compared to R4 (have been to Dampier Straight and Misool), Komodo, Wakatobi, Lembeh, Ambon and Gorontalo...very disappointing. But the resort we stayed at (Virgin Cocoa), was very nice.