On Satawal, navigational knowledge belonged to lineages and was released in stages, and the pwo ceremony that initiated a navigator carried obligations to the community as well as a body of technique. To hand that knowledge to outsiders was not an ordinary decision.
Mau Piailug made it on a judgement about the future. Younger men on Satawal were not taking up the training, ships and engines had made the canoe seem unnecessary, and he concluded that the knowledge would die with his generation if it stayed where it was. He taught Nainoa Thompson and others in Hawaii through the late 1970s and 1980s, in part by building a star compass out of coral on the ground.
In 2007 he conducted a pwo ceremony on Satawal, the first there in decades, initiating a group of navigators that included several of his Hawaiian students. He died in 2010.
What followed is a Pacific-wide revival: voyaging canoes built and sailed in Hawaii, Aotearoa, the Cook Islands, Samoa and elsewhere, and a circumnavigation by Hokule'a between 2014 and 2017. This is living knowledge held by the communities that practise it, taught within their own institutions and on their own terms. The atlas records that it exists, who carried it and how it was passed on. It does not teach it, and the ceremonial dimension of pwo is named here as belonging to Satawal rather than described.