The Itata is the only substantial shipwreck in Middle Harbour and one of the strangest dive sites in Sydney. She was a three-masted iron barque of 950 tons, 62 m long, built by R. and J. Evans at Liverpool in 1883 for the Newark Shipping Company.

On 12 January 1906, loading coal at Newcastle, a cargo of nitrate in one of her holds caught fire; a series of explosions blew planking and debris high into the air, brought down her masts and left the iron hull gutted and twisted. Towed to Sydney and judged too badly damaged even for use as a coal hulk, she was run into the head of Salt Pan Creek off Middle Harbour and abandoned, giving the little bay its local name of Wreck Bay. What remains is the lower iron shell of the ship lying in shallow, silty water surrounded by mangroves and bushland, part of it awash at low tide, the rest in 2–10 m.

There is no superstructure and no fittings to speak of; the interest is in the ribs and plating of a Victorian iron sailing ship and in the fact that it is there at all, a mile from suburban Castlecrag. Sydney Dive Charters lists it plainly: 'great for training dives in limited visibility'. Divers use it to practise wreck-specialty skills, line-laying, and the kind of zero-visibility buddy contact that harbour diving occasionally demands.

Marine life is sparse in the silt but not absent – bream, mullet, toadfish, small crabs and the occasional seahorse on the plating – and the mangrove edge is rich in juvenile fish. It is not a dive for scenery or for beginners without a guide, and the Abyss blog's account of a Chilean warship sunk in a 1917 collision at 30 m is fiction; the hulk is British, burnt, and shallow. The Itata suits instructors, wreck and maritime-history enthusiasts, and anyone collecting Sydney's odd corners; the wreck is protected and must not be disturbed.

Middle Harbour, in Salt Pan Creek (locally 'Wreck Bay') between Castlecrag and Castle Cove, upstream of the Spit Bridge and Sugarloaf Bay. Reached by small boat from the Roseville Bridge ramp (10 minutes downstream) or from the Spit/Clontarf (20 minutes upstream, through the Spit Bridge opening if the mast height requires it). Sydney Dive Charters lists it as a 10 m training site.

There is no practical shore access through the bushland reserve. Anchor clear of the hull and remain within the bay, which is a no-wash zone.

Completely sheltered from swell and most wind, so it is diveable in any weather – the limiting factor is visibility, which is nil after rain and rarely more than 2–3 m even in a dry winter, because the creek is fed by suburban stormwater and has a deep silt bottom. Tidal flow is slight; a flood tide brings the cleanest water. It is best treated as a deliberate low-visibility exercise rather than a sightseeing dive.

Descend beside the hull on a line, follow the plating by touch and torch around the outside of the iron shell at 4–8 m, practise line-laying and buddy contact in the poor visibility, and return up the same line. No penetration; the interior is silted and the plating fragile.

Sydney Dive Charters – occasional wreck-specialty and limited-visibility training dives ('great for training dives in limited visibility'); otherwise private boats and clubs.