South Head

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

Four old anchors and two unidentified structures off the head, each with a position and a depth. Heritage that nobody had recorded.

The South Head map

Anchor 1

−33.831488, 151.282150 — 10 m

An Improved Martin Anchor, as described in the 1911 Encyclopædia Britannica, which dates the design somewhere between 1852 and 1894. The angle between the arms and the two plates is not quite right for the drawing — most likely the bolts have gone, which the sea urchins living in it would support.

Anchor 2

−33.831049, 151.281595

Anchor 2

Anchor 3

−33.830551, 151.281336 — 13.6 m plus tide

A structure like a stock, lying under the anchor

Anchor 4

−33.831946, 151.284106 — 19 m plus tide

Anchor 4

Structure 1

−33.832704, 151.279256 — 7 m

Structure 2 — a hull?

−33.832569, 151.279501