The Seamaster Cosmic was introduced in 1967 and produced into early 1970s. Omega was “getting with the times” and Cosmic represented a radically different design philosophy compared to the traditional looking 50/60s Seamasters. The results speak for themselves.
Finnish advertisement from 1969. It states that Cosmic is made for an “active man” and compares the monocoque case to a shell of a tortoise which the ad calls “a masterpiece of nature” because it has “no unnecessary gaps” and therefore offers great protection.
Cosmic features a funky monocoque case (which often keeps the movement in pristine shape, so the old ad was not bullshitting) and many interesting dial variants with no-date/date/day-date options. C-case appears bigger on the wrist than the 35mm diameter suggests. Lug width 19mm. Surprisingly, the beveled caseback makes the watch really comfortable to wear.
