The reefs off The Entrance are known collectively as The Bommies - part of Tuggerah Reef - and Muddy Puddle Diver describes the area as a popular sport fishing, spearfishing and dive site with several shallow sites. PJ Cove is one of these, and the name almost certainly refers to the Port Jackson sharks that are common on shallow NSW reefs from winter into spring, when they gather to breed and lay their spiral egg cases in crevices. The bommies are patches of sandstone reef rising from sand, with coves, ledges, boulders and gutters in relatively shallow water.

The Terrigal Underwater Group's description of the wider system as a series of shallow sites that are total fish soup fits well: yellowtail, silver sweep, one-spot pullers and mado fill the water, eastern blue gropers and red morwong work the reef, and wobbegongs, fiddler rays and Port Jackson sharks rest on the sand and in the ledges. Kelp covers the tops, with sponges, sea squirts and encrusting growth on the sides, and nudibranchs and cuttlefish are common. Shallow depths mean long bottom times and good light, making the site suitable for Open Water divers and for photographers who want wide-angle shots of fish and sharks.

The same shallowness means swell matters - the bommies break in big seas and surge is noticeable on the tops. Because the area is also heavily fished and spearfished, expect boats and occasional line. For divers, it offers an easy, fishy reef between Terrigal and Norah Head, and with the existing Inner and Outer Bommies entries it rounds out the Tuggerah Reef system.

Launch at the Norah Head boat ramp in Cabbage Tree Bay (Cabbage Tree Harbour) and run south about 10-15 minutes, or from Terrigal Haven north past Bateau Bay for around 25 minutes. Local knowledge is needed to find the specific cove; The Entrance channel itself is shallow and bar-affected and is not a practical launch point for dive boats. Parking with trailer bays is available at Norah Head ramp.

Exposed to swell from the north-east through south-east; the shallow bommies break in big seas, so plan for swell under about 1.2 m and light winds. Tuggerah Lakes outflow through The Entrance channel can reduce visibility for days after heavy rain, especially on the ebb tide. Calm winter mornings with westerly winds give the best conditions, and a north-east sea breeze commonly ruins summer afternoons.

Anchor in sand beside the reef, explore the cove and ledges at 8-14 m looking for resting Port Jackson sharks, and work a loop back to the anchor. Keep an eye on surge over the shallower bommie tops.

Occasional trips by Central Coast Divers and Terrigal Underwater Group; mostly private boats.