The Agincourt is one of the timber-trade wrecks that make Hamelin Bay a small underwater museum. Divingwawrecks describes a 433-ton, 40 m wooden barque launched in 1863 and owned in Adelaide; marinelife.org.au gives her as a 131.9 ft barque launched at Sunderland in 1863. She arrived in Hamelin Bay on 17 February 1882 and was fully loaded with timber sleepers when a north-west gale set in. She dragged her anchors and struck a reef, and with water coming in faster than the pumps could clear it, the master deliberately drove her ashore. The crew's lifeboat capsized and the carpenter drowned trying to reach shore just 100 m away.

After more than 140 years the wreck is in remarkable condition. The lower hull is intact, with the cargo of sleepers still stacked in the middle, and marinelife.org.au notes an upper hull section about 5 m inshore with seven chainplates and an iron water tank between the two sections. The wreck is heavily vegetated but supports plenty of small fish, and it lies on sand in 5-6 m, easily seen from the surface.

It is an ideal first historic-wreck dive and an excellent snorkel on calm days, and it can be combined with the Chaudiere a few hundred metres south.

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 is about 900 m north of the ramp and 260 m north of the Chaudiere, south of and inshore of Inside Rock, roughly 100-120 m off the beach. Snorkellers can walk along the beach and swim out; it is easy to spot from the surface.

Divingwawrecks gives a limit of under 1.5 m swell and visibility under 10 m. The sandy bottom stirs easily with swell; dive on calm summer days with easterly winds. 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.

Swim or boat to the site, descend at the stacked sleepers amidships, circuit the lower hull, then look 5 m inshore for the upper hull section with its seven chainplates and the iron water tank between the sections. Snorkellers should stay within easy reach of the exit point and swim with a buddy; scuba divers at these depths need no safety stop but should ascend slowly and surface near the float.

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