A track chart showing the position of H.M.S.V. "Hydra" each day at noon when in search of the Marion Shoal, when surveying near Aguhlas and also when making a passage from Danger Point to Algoa Bay and from thence to Table Bay and Simons Bay between the 12th day of October and the 24th day of November in the year 1853.

Reported position of the Marion Shoal - Latitude 37° 26' S. Longtitude 26° 56' East.