The Kelloe is a deep wreck for the very experienced, sitting upright on sand beside a reef edge 1.25 km off Little Bay. She was an iron-hulled collier built by J. Laing of Sunderland in 1866, about 50 m long and 8 m wide, displacing 500 tons and driven by a 70 hp two-cylinder compound engine by G.

Clark. Named after a Durham coal town, she worked out of Hamburg before passing through several owners to the Wallarah Coal Company in 1891. At about 1.30 am on 12 May 1902, carrying coal from South Bulli to Sydney under Captain Hector Boyle, she was struck on the starboard side by the wooden steamer SS Dunmore north of Botany Bay.

Within 15 minutes the Kelloe sank stern first with her engine still running; all 15 crew were rescued. An inquiry blamed the Dunmore's second officer for a poor lookout. Eric Buchannan found the wreck around 1970 and for years it was known as 'the Cronulla'; John Sumner's team made the first recreational dive on 27 August 1978, and a recovered telegraph gauge engraved 'Kello' confirmed her identity.

She lies in 48–51 m, bow north. The boiler stands 3–4 m off the bottom and is the best landmark. The engine was intact and upright until 1996–97 but is now badly damaged, possibly by ships' anchors, with collapsed cylinders and scattered conrods; the condenser has opened.

The driveshaft runs aft, breaking before the three-bladed propeller (two blades broken), with rudder remains beyond. Forward are several large winches, the bowsprit and two enormous anchors, one upright with its shaft still able to pivot. The hull is flattened and messy, although a large hole lets divers pass through.

Divers have met humpback whales, dolphins with calves, a 2.5 m sunfish and a small mako shark here. Visibility is generally good. Because of the depth and the risk of current building during decompression, it demands twin cylinders or a pony bottle at minimum, and today is best done on trimix.

Boat only. From the Botany Bay ramps (Kyeemagh, Foreshore Road, Bonna Point) run out past Cape Banks and north along the coast to off Little Bay – about 20 minutes. Long Bay (Malabar) ramp is closer on calm days.

McFadyen's GPS is 33° 59.0884' S 151° 15.9854' E, about 1.25 km offshore. Drop a shot onto the wreck and rig a deco station; anchoring in 50 m in current is unreliable.

Fully exposed offshore site. Swell from the north-east through south over about 1.5–2 m rules it out, and a southerly change can make the ascent and pick-up dangerous. Current is the key factor: the East Australian Current can pick up during the dive, and one team reported a current rising while they were down that made decompression very difficult.

Plan with a drifting deco station and surface cover. Visibility has generally been good (most logged dives good to very good), though the very first attempt had 25 cm. Winter westerlies give the best days; humpback whales pass in June–November.

Shot the boiler (rising 3–4 m off the bottom), descend and look at the engine remains and condenser, follow the driveshaft aft to the broken propeller and rudder, then return forward past the winches to the two big anchors and bowsprit at the bow. Keep to 15 minutes on air/nitrox deco; McFadyen's sample profile of 15 minutes needed stops of 2 min at 9 m, 4 at 6 m and 18 at 3 m.

Trimix recommended (18/35 or similar) with EAN50/O2 deco; on air max 15–16 min bottom time. Twin cylinders or large tank plus pony bottle minimum. Drifting deco station advisable.

Protected historic shipwreck.

Abyss Scuba Diving (Ramsgate) runs occasional deep/technical trips; otherwise private boats and technical clubs.