Few Sydney wrecks have a stranger history than the Meggol. She was launched on 10 November 1919 as HMS Wexford, an Aberdare-class minesweeper of the Royal Navy, built too late for the war she was designed for. Sold in 1921 to the Brisbane Tug and Steamship Company she became the excursion steamer Doomba, running day-trippers from Brisbane to Stradbroke Island for eighteen years.

On 3 September 1939 she was requisitioned and commissioned as HMAS Doomba, serving through the Second World War as a minesweeper, anti-submarine patrol vessel and submarine-detection ship along the east coast. Paid off in March 1946 and sold to shipbreakers, she escaped the torch when Meggitt Ltd, a Sydney vegetable-oil firm, bought the hull around 1951 and renamed her Meggol, using her as a floating oil storage and refuelling barge on the harbour until 1970. On 8 or 9 December 1976 she became the second vessel scuttled on the new Long Reef artificial reef, going down beside the Dee Why ferry sunk six months earlier.

The wreck sits upright on sand at 49 m with the deck originally at 43 m. It is now badly deteriorated: the hull from the bow back to the first hold has fallen to starboard and lies almost level with the sand, the deck has largely collapsed, and rust has opened the plating so that you can look from one compartment into the next. What remains legible is a long, low warship hull about 70 m long with a series of former holds and oil tanks forward, the engine and boiler spaces amidships, and a steering compartment at the stern.

It is a wreck for those who enjoy reading structure rather than admiring intact ships. Fish life is shared with the Dee Why: bullseyes, nannygai and kingfish, with the occasional jewfish. The value of the Meggol is historical and as a second objective on a Dee Why dive; twenty metres of sand separate the two, so with a compass bearing and reasonable visibility a team can tour both within one bottom-time budget.

It suits experienced decompression divers who already know the Dee Why and want to see the only Royal Navy minesweeper hull diveable in NSW.

Boat only. Charters and private boats usually launch from the Roseville Bridge ramp on Middle Harbour or Rose Bay/Manly in Sydney Harbour and run north up the coast past North Head, Manly and Dee Why (roughly 45–60 minutes at cruising speed), or from the Akuna Bay/Pittwater ramps and run south past Barrenjoey (similar time). There is no all-weather ramp on the Northern Beaches ocean coast itself.

The wrecks lie on a flat sand plain and cannot be seen from the surface; you need accurate GPS and a sounder, and must drop the anchor or shot line directly onto structure because it will not hold in the sand. A drifting decompression station with spare gas is the normal arrangement. Most divers locate the Dee Why first and swim the 20 m across the sand to the Meggol, which lies to starboard of the ferry's eastern end.

The Long Reef wreck ground is 4–5 km offshore in open water with no lee. Any southerly or north-easterly swell above about 1.5 m makes anchoring on the wreck and the long decompression hang unpleasant or unsafe; charters generally want under 1 m swell and under 15 knots. Surface current from the East Australian Current can run north–south across the site even when the bottom is still, so a drifting deco station or a strong anchor line is essential.

Visibility is best from late autumn through winter (15–25 m) when the water is clear and cool; summer brings warmer water but more plankton and thermoclines. Avoid the days after heavy rain when the Narrabeen and Hawkesbury outflows dirty the inshore water. Mornings before the sea breeze are calmest.

Descend on the Dee Why shot, cross the sand at 47 m to the Meggol's bow, and run aft along the collapsed forward holds to the steering compartment at the stern, then back along the other side. Do not enter the unstable forward hull. Return to the ferry and ascend its shot line for decompression.

Decompression dive. Typical plans use trimix (e.g. 21/35) or air/EANx with 50% and/or 100% O2 deco gases; 20–25 minutes bottom time gives 30–50 minutes of decompression. Twin cylinders or CCR with bailout, reel/line for any penetration, DSMB and surface support boat mandatory.

Silt inside compartments; several fatalities have occurred on this wreck group, so treat penetrations as overhead dives.

No scheduled recreational charters. Sydney Dive Charters (Rose Bay/Manly) runs technical charters to the Long Reef wreck area on demand for T1/Tec45+ certified divers; otherwise private boats and technical dive clubs launching from Roseville, Akuna Bay or Rose Bay ramps. Expect a handful of visits per year.