One consequence of that initiative was that, in 1858, the Royal Navy survey ship completed the first detailed survey of the atoll, resulting in the "Plan of the Pratas Reef and Island", J. Richards and others, April 1858, being published by the British Admiralty. On the resulting chart three positions are proposed for a lighthouse: on Pratas Island, on the north-east corner, or on the southern edge near where HMS "Reynard" had stranded. In the north-east corner of the lagoon the chart notes "Anchorage for junks", indicating regular use by fishing and other small vessels taking shelter. The chart's rubric noted that the available safe draft for vessels entering was only , so it was restricted to relatively small vessels only.