South Head

South Head, Sydney: the anchors off the point with GPS positions and depths, including an Improved Martin anchor from the 1800s.

Anchor 1 -33.831488 151.28215 depth 10 m

"Improved Martin Anchor" described in The Encyclopædia Britannica Eleventh Edition (1910–1911) dated sometime between 1852 and 1894. The angle between the hands and the two plates is different, but probably the bolts have disintegrated as the presence of the sea urchins suggests.

Anchor 2 -33.831049 151.281595

Anchor 3 -33.830551 151.281336 depth 13.6m + tide

Structure like a stock lying under the anchor

Anchor 4 -33.831946 151.284106 depth 19 m + tide

Structure 1 -33.832704 151.279256 depth 7 m

Structure 2 (hull?) -33.832569 151.279501