The Cliffs is one of the rarest dives in the Heron Island programme. It lies on the ocean side of Wistari Reef, the big reef west of Heron, and there are no moorings; divers make a free descent to 6-7 m, follow a gradual slope, and then reach the signature feature: a wall that drops straight down to 25-30 m before flattening out onto sand. The wall is decorated with large gorgonian fans hung with feather stars, and overhangs along the face are packed with glassfish.

Loggerhead turtles are frequently seen, and schooling pelagic fish move along the wall in the clearer offshore water. The sense of scale, with a sheer face falling away below, sets it apart from the gentler slopes and bommies of Heron Reef. Because of its exposure, the site is dived only a handful of times each year when weather allows, and only by experienced divers who are comfortable with free descents, live-boat pick-ups and depth.

It is not a site to request on your first day; instead, let the dive team know you are interested and be ready if a calm window appears. The Cliffs suits Advanced divers with good buoyancy control and experience in open water. For those lucky enough to dive it, it is often the highlight of a Heron trip.

It was grouped with several other sites in the earlier database pass and now has its own row. Being on an exposed outer face, the site receives clearer water than the lagoon-side sites, and on the rare calm days when it is dived, visibility can exceed 25 m.

Heron Island is 72 km north-east of Gladstone. Fly or drive to Gladstone, then take the Heron Islander ferry from the Gladstone Marina terminal (72 Bryan Jordan Drive; check-in from 7:45 am, departs 9:30 am on scheduled days, about 2 hours), or transfer by seaplane or helicopter. Dive gear is carried on the ferry in addition to baggage.

On the island, the dive centre sits beside the harbour; boats leave the jetty for three dives daily and most Heron Reef sites are 5-15 minutes away. The Cliffs is on the exposed ocean side of Wistari Reef, the large reef immediately west of Heron across Wistari Channel; the run takes about 15-25 minutes and there is no mooring, so divers make a free descent from a live boat.

Heron Reef sites are chosen on the day by wind and tide. The prevailing south-east trade winds (strongest April-September, often 15-25 knots) make the southern and south-eastern reef edge rough, so the sheltered northern and western sites are dived most. Northerly winds in spring and summer reverse this.

The tidal range is up to 3-4 m and currents run strongly around the reef edge and through Wistari Channel on springs; visibility is usually best on the incoming tide. Cyclone season is November-April; summer storms and plankton blooms can drop visibility to 10 m. Stingers are uncommon this far south but present in summer.

The Cliffs is on the ocean side of Wistari Reef and needs very calm conditions with little swell; it is dived only a few times each year, usually in light winds or calm spells between trade-wind periods.

Free-descend to the slope at 6-7 m and follow it out to the lip of the cliff. Drop down the wall to 20-25 m (not deeper than your certification), move along the face looking into the overhangs, then ascend slowly up the wall and finish the safety stop on the slope with an SMB deployed for the live boat.

Heron Island Resort Dive Centre is the only operator: three guided boat dives a day (about 9 am, 11 am and 3 pm) plus scheduled night dives, from the resort jetty; sites are rotated by tide and wind. Access requires a stay at Heron Island Resort (or the University of Queensland research station). The Cliffs is dived only a handful of times a year when weather allows.