Jack E. Churchward is the great-grandson of James Churchward, the creator of Mu. In 2011 Jack republished what he describes as the definitive edition of James’ 1926 The Lost Continent of Mu which includes a new index and added appendices. It is still just the concoction of a fertile mind. My scepticism and that of many others is reflected in a recent blog from Dale Drinnon(a).
>For the record, Jack is quite sceptical of his great-grandfather’s theories and has republished some of the earlier material in order “for the reader to evaluate the basis of his argument,”<
Jack has also a promotional website(b), where he candidly wrote(c) that “the Troano Manuscript, as a reference for the sinking of Mu, must be removed from the list, if there is to be any legitimacy accorded to an evaluation of Churchward’s theories on Mu.” Jack was highlighting the unreliability of James’ translation of the Troano Manuscript, influenced as it was by the earlier seriously flawed attempts by Bishop Diego De Landa (1524-1579), Brasseur de Bourbourg and LePlongeon. Jason Colavito has added further comments(d) regarding Jack’s blog.
Jack continued to explore his great-grandfather’s misguided ideas with the publication of The Stone Tablets of Mu  in August 2018.
>In 2019, Jack published Crossing the Sands of Time: An Examination of the History and Legends of the Great Uighur Empire . We are told that “This book was motivated by the author’s interaction with Uyghur scholars and the marked difference between the real history and that espoused by his great-grandfather, James Churchward. During the research, other theories surfaced and are addressed as well. Included are appendices containing all the elder Churchward’s mentions of the Uighurs allowing the reader to judge for themselves the veracity of his pronouncements.”<