The Aquarium, as regular visitors to North Solitary Island have taken to calling this patch of sheltered reef near Anemone Bay, does not have any single headline feature the way Elbow Cave has its anemone beds or the Boulders has its giant groper and canyon-scale topography — its appeal is simply the extraordinary overall density and diversity of resident reef fish packed into a shallow, easy 8 to 18 m of water. As at the rest of the southern section of North Solitary Island, the site sits in the lee of the island, giving it good shelter and consistently excellent visibility given the distance from any mainland river outflow. Schooling bullseyes, sweep and various wrasse and damselfish species crowd the reef in numbers that repeat visitors describe as genuinely aquarium-like, moving in dense, swirling masses around the coral and rock structure rather than the more scattered distribution typical of many reef sites.

Turtles, wobbegong sharks and moray eels round out the site's resident cast, and the shallow average depth allows for long, unhurried dives well beyond the 30-40 minutes typical of the deeper Pimpernel Rock or Boulders sites elsewhere on this trip. Because this is very much a supplementary rather than headline site, it is typically worked into a broader day of North Solitary Island diving alongside Anemone Bay and Fish Soup, filling the role of an easy, colourful, low-stress dive to round out a demanding day. For photographers and less experienced divers on a North Solitary Island trip, it offers one of the most reliably enjoyable, unhurried experiences of the whole excursion, without needing any particular skill or experience beyond basic Open Water competence.

Wooli Dive Centre departs from the Wooli River wharf; trips to North Solitary Island run about 75 minutes each way, weather dependent, with a minimum group size typically required.

North Solitary Island sits fully in the open ocean and trips depend on a genuinely settled weather window; the Wooli River bar can be dangerous in a big swell or strong outgoing tide. Visibility is normally excellent (15-30 m).

Descend onto the reef at 8-10 m, spend the dive moving slowly through the dense schools and resident fish population rather than covering ground quickly, and finish with an extended, unhurried ascent given the shallow average depth.

Wooli Dive Centre includes this site on North Solitary Island trips alongside Anemone Bay and Fish Soup, conditions permitting.