Parker Bommie is a single large coral and rock pinnacle off Great Keppel's exposed south-eastern tip, rising from about 17 m to within a metre of the surface. It is less visited than the sheltered bays because it needs calm weather, but local descriptions call it an invertebrate garden of brilliant colour and variety, and it rewards the wait. The bommie's sides are covered in sea fans, cup sponges, tube worms and staghorn corals, with black coral trees on the deeper faces.

Schooling batfish and sweetlips hang off the down-current side, angelfish work the ledges, and there is a chance of manta rays, reef sharks and sea snakes. Because the site is compact, a dive consists of circling the pinnacle and slowly working up through the depth range. The upper part can have strong surge, while the base is usually calmer.

It is a good site for wide-angle photographs of fans and sponges against the blue when visibility allows, and for macro life hidden among the invertebrates. Parker Bommie is best suited to experienced divers: it is exposed, has no mooring and can have current. When conditions are right, it is one of the most colourful dives in the Keppels.

Because Parker Bommie is visited so seldom, it tends to have larger, less disturbed invertebrate colonies than the busier sheltered sites, and the black coral trees in particular are unusually well developed for such shallow water. Expect to spend a lot of the dive looking closely: gobies and small shrimps live on the whips, and nudibranchs graze the sponges. Surface intervals are best spent back in the lee of the island rather than near the exposed point.

Drive 40 km (about 40 minutes) from Rockhampton to Yeppoon, then 7 km south along the Scenic Highway to Keppel Bay Marina at Rosslyn Bay Harbour, where there is free and paid parking. Freedom Fast Cats and Keppel Konnections ferries run to Great Keppel Island (Fisherman's Beach) in about 30 minutes; Keppel Dive & Water Sports picks up certified divers from the island. Parker Bommie lies off the south-east tip of Great Keppel, about 15-20 minutes by dive boat from Fisherman's Beach or around 40 minutes by private boat from Rosslyn Bay.

There is no mooring; boats anchor on sand nearby in calm weather only.

Keppel Bay is exposed to the prevailing south-east trades (strongest April-September) and to summer northerlies. Parker Bommie is directly exposed to south-easterly wind and swell and is dived only in calm spells (winds under about 10 knots, swell under 1 m) or light northerlies. Surge over the shallow top makes the upper bommie unpleasant in any swell.

Currents sweep the south-east point on spring tides; plan for slack or neaps. Visibility 8-15 m, best in winter.

Descend down-current of the bommie to the base at 15-17 m and circle it slowly, checking the black coral trees and sea fans. Spiral upward in stages, spending time at 8-10 m among the sponges and tube worms, and complete the safety stop in the lee of the bommie rather than on its surge-swept top.

Keppel Dive & Water Sports (PADI 5 Star, based on the Spit at Great Keppel Island next to Great Keppel Island Hideaway) runs guided boat dives to the Keppel sites most days, weather permitting, plus courses and Discover Scuba; site choice is made on the day according to wind. Private boats from Rosslyn Bay also dive here. Parker Bommie is dived occasionally in calm conditions for experienced divers.