The Cumberland is one of the oldest wreck sites on the South West coast. Marinelife.org.au describes a 444-ton wooden colonial trader, on passage from Newcastle, New South Wales, to Fremantle, that was lost on a sandbank south of Cape Hamelin with no loss of life. Divers found the wreck in 1981. An anchor, a cannon and timbers remain, but the weedy bottom makes the relics hard to see, and material recovered from the site is displayed in the Augusta museum.

The source lists the vessel with the date 1829; the loss appears to have occurred in the early years of the Swan River Colony (founded 1829), which makes it one of the earliest colonial-era wrecks in Western Australia. The date should be confirmed against the WA Museum shipwreck database before publication.

This is a site for wreck-history enthusiasts with a boat and local knowledge. In 3-8 m of water it is technically easy, but finding the remains in weed requires patience. Like all wrecks older than 75 years it is protected under heritage legislation; nothing should be moved or taken.

Combine it with a visit to the Augusta museum to see what came from the site.

Hamelin Bay was a timber port from the 1880s, when a jetty built in 1882 and extended in 1898 served M. C. Davies' milling operations. It was notorious for wrecks in bad weather because it is exposed to the north-west gales of winter storms; the 22 July 1900 storm alone wrecked several ships, and only the old jetty piles remain today. The bay is now a recreation zone in the Ngari Capes Marine Park, and every wreck in it older than 75 years is protected.

Hamelin Bay is on the coast west of Karridale, about 35 km south of Margaret River and 30 km north of Augusta, reached via Caves Road and Hamelin Bay Road. Park at the boat ramp/jetty area beside the Hamelin Bay Holiday Park. Launch at the Hamelin Bay boat ramp - marinelife.org.au warns it is narrow, slippery and swell-exposed, and a 4WD may be needed.

The wreck lies on a sandbank south of Cape Hamelin, south of Hamelin Bay; the position is not published, so local knowledge is required.

Exposed south of Cape Hamelin; dive only in calm summer conditions. The weedy bottom makes relics hard to see. General pattern on the Capes and Leeuwin coast: summer mornings often have light easterly (offshore) winds before a south-westerly sea breeze, and long-period south-westerly groundswell can arrive on otherwise calm days; winter fronts bring big swell and north-westerly winds.

Check the Bureau of Meteorology swell forecast, not just the wind.

Anchor near the sandbank, search slowly through the weed for the anchor, cannon and timbers, and return to the boat. Agree a turn pressure before descending (half gas, or a third where current is likely), carry a DSMB, and make a 3-minute safety stop at 5 m.

No operator; private boats and wreck enthusiasts. Nearest dive services: Swan Dive (Busselton/Port Geographe) for fills, hire, nitrox and charters; no dive shop in Margaret River or Augusta.