Keith S. Chambers and Doug Munro (1980) identified Niutao as the island that Francisco Mourelle de la Rúa sailed past on 5 May 1781, thus solving what Europeans had called "The Mystery of Gran Cocal". Mourelle's map and journal named the island "El Gran Cocal" ('The Great Coconut Plantation'); however, the latitude and longitude was uncertain. Longitude could only be reckoned crudely as accurate chronometers were not available until the late 18th century. Laumua Kofe (1983) accepts Chambers and Munro's conclusions, with Kofe describing Mourelle's ship "La Princesa", as waiting beyond the reef, with Nuitaoans coming out in canoes, bringing some coconuts with them. "La Princesa" was short of supplies but Mourelle was forced to sail on – naming Niutao, "El Gran Cocal" ('The Great Coconut Plantation').