Speedmaster Professional

The Speedmaster began in 1957 as a watch with a stopwatch built into it. The long central hand measured elapsed seconds, smaller counters accumulated minutes and hours, and a numbered ring around the face could convert the time over a known distance into speed. Its original setting was racing, not space.

NASA's qualification of the Speedmaster for crewed missions in 1965 changed the watch's history. Earlier-generation Speedmasters went on to the lunar surface during Apollo. Their black faces, three small counters and pale hands became associated with that work, and later versions retained much of the arrangement. “Moonwatch” now describes a long family of watches, not a claim that every reference went to the Moon.

The mechanisms did not stand still. The early calibre 321 gave way in regular production to the 861 in 1968. Both were wound by hand, but they used different mechanisms to control the stopwatch. Later came the 1861. Omega's archive lists both 861 and 1861 within the long-running 3570.50 reference, a reminder that even one catalogue number can span a change inside.

The 2021 Professional generation introduced calibre 3861, with a Co-Axial escapement and Master Chronometer certification. Its familiar 42 mm steel case still widens on the right to protect the crown and pushers. Buyers could choose acrylic at the front and a solid back, or sapphire front and back. The outward layout changed much less than the testing and mechanism behind it.

Alongside that development, Omega revived the calibre 321 in a separate modern watch. Its smaller, symmetrical case returns to a form used before the familiar 42 mm Professional. The two branches take different approaches to the same history: one continues revising the regular production watch, while the other rebuilds an earlier mechanism.