Omega debuted the Seamaster family – like this Seamaster here, a Cosmic Ref. 166.026 – in 1948 to celebrate the company’s Omega’s 100th anniversary loosely based upon designs made for the British Royal Navy near the end of World War II, and was, in essence, a “splash-proof” dress watch – it now holds the honor of the longest running model since Omega’s founding in 1848. 


Omega subsequently debuted the Ref 166.0118 in 1971 and produced through 1980.  Of curious note, the Calibre 1480 (17 jewels) and 1481 (21 jewels) were one of few movements developed jointly with Tissot in the early 1970’s – however, Tissot only produced the 21 jewel variant (which Tissot named the 2481).


Omega’s design of the first Seamaster, the 300, drew influence from older waterproof watches worn on the wrists of the British military during WWII.  However, what would initially distinguish the first Seamaster from its other predecessor watches from Omega competitors was its rubber O-ring gasket, which separated the dive watch from other lead or shellac gaskets which were more susceptible to temperature changes.  Instead, Omega’s rubber gasket prevented any water infiltration in severe temperature changes ranging between -40° C to 50° C. 


In 1955, the Swiss Laboratory for Watch Research tested 50 Seamaster cases down to a depth of 60 meters, all with rubber O-rings – all passed with no water infiltration.  Omega engineers was so confident of the Seamaster’s durability, they attached one to the outside of an aircraft and flew it over the North Pole in 1956.  The Seamaster 300 performed so well, in fact, that Jacques Cousteau’s team used it during experimental dives in 1963 and beyond.


For the past 70+ years, Omega has produced a staggering array of Seamasters to suit a variety of needs; from solid gold dress watches to solid blocks of stainless steel used for dive watches, from soccer timers to world timers, the Seamaster has seen them all.  While other watch companies have various families to cater to various customers, Omega’s Seamaster is unique in its versatility: at one point or another there has been a Seamaster for just about everyone.


In the hierarchy of Omega dress watches, the Seamasters were somewhere in the middle; above the Geneve but below the Constellation.  Seamasters and Constellations shared many of the same movements, but Seamasters were not chronometer tested nor as elaborately finished. 


This Omega comes with a generic stainless-steel bracelet strap, nylon ZULU strap, springbar tool, and Pelican travel case.

1960's Omega Seamaster Cosmic Ref. 166.026 Automatic, Calibre 565

  • DIAL: Original detailed Omega and Seamaster Cosmic-signed silver “sunburst” dial, with original hands. 


    CASE: Original 37mm (w/o crown, 38.5mm with) x 38mm stainless steel mono-bloc case, with sharp caselines.  Seamaster icon inscription on back of case is faded, but evident.  Case top retains its brushed finish.


    CRYSTAL: Omega-signed domed crystal, with subtle scratches near the two o'clock position but no cracks.


    BAND: Generic stainless-steel bracelet, which will accomadate up to an approx. 7.5 inch wrist.  This Seamaster also comes with a dark blue and red nylon NATO strap, with stainless-steel hardware.


    MOVEMENT: Original 24-jeweled Omega Calibre 565 automatic mechanical movement, which beats at 19,800 bph.


    CROWN: Original Omega-signed stainless-steel crown.