Cover franked with Great Britain 1912 1d bright scarlet GV issue (SG 357) tied by boxed 'PAQUEBOT' marking with good strike of undated circular 'TRISTAN DA CUNHA' type I cachet in purple alongside (SG C1) carried on the Barque 'Michelet' which called at the Island in September 1917 on its voyage to Australia. The 'Michelet' was one of only two vessels that called at Tristan da Cunha in 1917. The mail was disembarked at ADELAIDE in South Australia with ADELAIDE transit cds dated OCT 25 1917 on reverse. The cover is addressed to Oxted, Surrey with a slightly scratched out OXTED arrival cds on front date 4 DEC 1917 and then re-addressed to Watford, Herts. A superb new discovery and arguably the finest known cover from the Michelet. 2023 RPSL certificate accompanies.