The northern most island in the Bunaken National Park is Nain. Diving here has similar topography to the rest with impressive steep walls. Jalan Masuk offers the only way in for boat traffic due to the huge fringing reef that surrounds the island. There is often great viz of 35 meters and above and myriad smaller reef fish living in the coral plateaus here.
A large very deep pinnacle starts at 40 meters with caves at 60 but this is beyond recreational limits. Due to its remoteness from the other islands there is always the prospect of an encounter with big visitors , maybe even hammerheads or pilot whales.