Shark City is the second channel of the Maratua atoll near Nabucco and Nunukan Islands. It is a channel-and-slope dive with a shallow top, a steep reef shoulder, and frequent shark and ray encounters, so it suits experienced divers who are comfortable reading current and staying on a moving line. Most dives are made by following the reef shoulder with a clear current plan, which makes it a better fit for teams that can hold position, time the channel, and manage a moving pickup.