D. H. Lewis, in his article ‘Ara Moana: Stars of the Sea Road’ in the July 1964 issue of the Journal of the Institute of Navigation (pp. 278–88), speculates on how the Polynesians could have navigated to known distant destinations, but does not explain how the knowledge of die distant destinations on which he relies for his theories was gained by the supposed navigators. Before anybody can navigate to somewhere, someone must first have gone there and come back. Lewis does not tell us how the Polynesians gained their knowledge of the existence, location and size of New Zealand and Hawaii, and of the currents on these courses, on their outward voyages of discovery, and then used this knowledge to get home again. His statement that ‘it seems probable that the Polynesians steered by horizon stars until the zenith star showed that they had reached the right latitude, and then turned east or west’, obviously has no application to voyages of discovery which by definition were made without prior knowledge of the existence, latitude or size of the objectives. The alternative supposition that the discoverers were able to keep account of their courses from bearings on stars which were reputedly aligned with the destinations and the home islands overlooks the fact that such star bearings gave no clue whatever to longitudinal displacement. There was no practicable method whereby the discoverers could have known the longitudinal relationships of their discoveries and their home islands.