On this 1863 navigation map of the Manukau Bar, the hatched lines represent sandbanks. The lines with numbers show the course ships needed to follow to safely cross the bar. The numbers themselves are soundings, showing the depth in fathoms (one fathom = 1.83 metres). Also shown is the spot where the Orpheus foundered earlier that year, with large loss of life – it had relied on an out-of-date map when crossing the bar.
Te whakamahi i tēnei tūemi
Auckland City Libraries - Tāmaki Pātaka Kōrero
Reference: NZ Map 3524
Permission of Auckland City Libraries Tāmaki Pātaka Kōrero must be obtained before any re-use of this image.