A fair number of different designs bearing the "Speedmaster" name have been produced over the years but it would be incorrect to
consider them all to be older or newer versions of the "Speedmaster Professional". Production and sale of most 'other'
Speedmasters ran 'parallel' to the continued production of the "Professional" which has remained pretty much unchanged
for over 30 years.

The Speedmaster, A Chronology

Year Model Reference(s)   Description
1942 OT 2466 Calibre 321 (27 CHRO C12) The first Omega Chronogograph movement with 12 hour totalizer. Used in numerous models including OT 2466
1957 CK 2915 The Speedmaster. A water resistant chronograph with tachometer scale. (Broad arrow shapped hands)
1959 CK 2998 Case size increased from 39 to 40mm. Hands change to 'dauphine' style instead of previous models Broad Arrow.
1963 ST 105.012   Model produced with assymetrically shaped case to provide better protection to the push buttons and winding crown.
1966 ST 145.012   Speedmaster's first space mission. Worn by Edward White. Speedmaster is renamed "Speedmaster professional"
1968 ST 145.022 Calibre 321 movement is replaced with the new 861 calibre.
1969 ST 145.014 Speedmaster mkII with 861 calibre movement. (ST145.014 ref in Steel. BA145.014 ref in Gold)
1971 ST 176.0002 Speedmaster mkIII, calibre 1040, Automatic movement with Date.
1973 ST 378.0801 Speedmaster 125. Omega's first automatic chronograph with chronometer certification. This is a limited series of only 2000 pieces to mark Omega's 125th anniversary.
1973 ST 176.0009 Speedmaster mk IV. Calibre 1040
1973 ST 388.0800 Speedsonic. F300Hz Tuning-Fork Electronic Movement. Calibre 1255
1974 ST 376.0012 Speedmaster Automatic. Calibre 1045. Day-Date. Also variations in case style such as 376.0014 -17 etc.
1977 ST 186.0004 Speedmaster Quartz with (LCD) Liquid Crystal Display. Calibre 1620. Also case variations.
1980 ST 345.0808 Speedmaster Professional. Special version with transparent case back. + Dial/Strap variations.
1984 ST 376.0806 Speedmaster mk V. Special version for the german market. Automatic Movement. Cal 1045
1985 ST 345.0809 Speedmaster Professional, Handwinding Cal 866. With Date and Moonphase.
1987 ST 376.0822 Speedmaster Automatic. Calibre 1045. Day-Date display
1991 ST 175.0043 Speedmaster Automatic. Smaller 39mm case. calibre 1155. With Date
1992 BA 145.0053 Speedmaster Limited edition of 50 units in Gold to commemorate the creation of the first 27 CHRO C12 movement in 1942. Cal 867 Skeleton movement and transparent case back.