Late 1960s production Longines diver chronograph Ref. 7981-1 in stainless steel, equipped with the legendary Cal. 30CH with flyback function. This is the rare first-generation “Big Eye” model.
Among watches fitted with the Cal. 30CH, it uses the largest 40 mm case, featuring a screw-back waterproof construction with a rotating bezel. The black dial with tachymeter scale and the distinctive oversized sub-dial known as the “Big Eye” give it a bold appearance. While many Cal. 30CH chronographs are known for their classical styling, this model clearly stands apart as a sporty diver-type chronograph.
The specifications differ between the early Ref. 7981-1 and the later Ref. 7981-2 and subsequent versions. This particular example is the extremely rare earliest specification, featuring the Cal. 30CH movement, slender luminous hour and minute hands, leaf hands in the sub-dials, and a caseback engraved with “LONGINES / WATERPROOF.”
It is accompanied by the original bracelet (fits wrists up to approximately 20 cm).
Longines’ in-house chronograph calibers, such as the Cal. 30CH, are considered masterpieces in the history of watchmaking, notably incorporating a flyback function as a standard feature—something rarely seen in other brands. These movements are perfectly established classics and will undoubtedly continue to be appreciated and recognized in the future.