When Tudor donates a unique watch to the Only Watch charity auction, the biennial event aimed at raising funds for research on Duchenne Muscular Dystrophy, it is usually in teasing mode. In 2015,? a unique Tudor Black Bay with a black bezel was presented, which led to the 79220N. Two years later, Tudor created the lefty Black Bay Bronze with a khaki green bezel, and in 2019 a full black, ceramic Black Bay, which gave us the recent BB Ceramic. For this year's edition of the charity event, Tudor comes up with another potential teaser, the Tudor Black Bay GMT One for Only Watch 2021 – at least, regarding the movement…The one-off Black Bay GMT One donated for Only Watch 2021 has a rather unique look in more ways than one. Selecting the extremely popular Black Bay is a no-brainer for Tudor and continues the tradition that started back in 2015. This year's edition sees the Black Bay GMT in an aged steel case, bezel and bracelet. The entire watch has been given a patinated look, including the bezel insert and, more importantly, the dial. But it's not just about the aged exterior! Look closely at the dial, and you get a hint of a possible next step for the Black Bay lineage. Ad - Scroll to continue with article The matte black dial has matte grey markings, almost blending into the background. What is important to note is that in the bottom half, you can see “GMT Master Chronometer” written. This means the standard MT5652 movement has been upgraded and now comes with the Master Chronometer certification as defined by METAS. This was first presented in the 2021 Black Bay Ceramic and now in this special one-off. Maybe, just maybe, the regular Black Bay GMT will soon be updated with a new Master Chronometer movement… we’ll see. The rest of the specifications for this Only Watch 2021 model are similar to the current Tudor Black Bay GMT now in collection, with the exception of the patinated manufacture movement visible through the caseback, something Tudor first did with the silver and gold Black Bay Fifty-Eight models presented at Watches & Wonders 2021.Created in 2005, Only Watch is a biennial fundraiser for research on muscular dystrophy – Association Monegasque Contre les Myopathies (AMM). Organized under the patronage of HSH Albert II de Monaco, the watches of the 9th edition will be auctioned by Christie's on Saturday, 6 November 2021. More details at www.onlywatch.com.