Name: The large rock at the site is marked on the SA Navy charts as "Noah's Ark", and is commonly referred to by local divers as "Ark Rock". The wrecks are associated with the rock by being nearby. There is a wreck of a barge just south of the rock, the wreck of a small steam-powered vessel to the west and a larger iron or steel vessel, probably the Parana (1862), to the north-west. Another small wreck of a steam-powered wooden vessel lies to the south of the barge wreck, near a small group of large rocks, and a third boiler lies near a small group of rocks some distance to the east. Depth: Maximum depth is about 14 m on the north side of the main reef and in the area of the main section of the Parana wreckage. Most of the area south of Ark Rock is sand bottom at 10 to 11 m depth, and most of the wreckage and rocks extend less than 3 m above the bottom. Topography: This is a huge flat-topped granite boulder standing on even larger granite outcrop which extends above the sand level. The exposed rock is about 55 m long from east to west and 30 m from north to south. Mostly sheer sided with small overhangs and some deep crevices. The bottom is sand, sloping very gradually from about 10m at the south of the rock to about 8m near Penguin Point. There are a few pinnacles around the main rock, including one to the west, and at least two to the south. Marine life: Noah’s Ark: There is a band of Black mussels and barnacles around the rock to about 1 m below surface, then Red-bait on deeper surfaces. The vertical surfaces and overhangs are heavily encrusted with organisms typical of the area and include sponges, crinoids, ascidians, sea cucumbers, hydroids and sea fans.