When Jacques Cousteau and Émile Gagnan developed the first open circuit SCUBA tank in the mid-twentieth century, they opened the door for growth within both commercial and recreational diving. Alongside this new technology arose the need for precision timepieces that were not only waterproof, but also maintained integrity at depth and decompression. Many watch brands sought to enter the field of dive tool watches, and Omega was no exception. With the release of the first Seamaster reference meant for professional diving in 1957, Omega began a journey towards technical precision and innovation for those willing to brave the depths of the ocean.

In looking at the design of the watches Omega was developing in the early 1970s, it is apparent that the Seamaster reference 176.004 "Big Blue" (named for the obvious reasons that it is both large and blue) took architectural cues from several references that were also being introduced in the late 1960s and early 1970s that echoed the futuristic ethos typical of the era such as orange hand of the so-called “PloProf” and the prototype Seamaster 1000 and the oversized tonneau-shaped case of the Flightmaster. It is, however, most similar to the reference 176.002 Speedmaster "Mark III", first introduced in 1971. The case is mountainous, summited by a uni-directional rotating bezel, with vertical brushed finishing throughout.

Given the expensive price tag of these watches at the time (reportedly 715 CHF), they were bought by those seriously interested in using them for their intended purpose of diving. Thus, it is difficult to find examples of the "Big Blue" in unmolested condition with original parts, making the current lot an incredible find for diving watch enthusiasts.