Chronomaster Aviator Sea Diver: this singular name belongs to one of the most original professional watches of the 1960s, combining an unparalleled number of functions with a timeless design. Created in 1961, this chronograph was produced for around ten years under several brand names, through a partnership between the Swiss company NIVADA SA and the American firm CROTON WATCH CO. This led to some of its dials bearing probably the most complicated name in watchmaking history: CROTON NIVADA GRENCHEN Chronomaster Aviator Sea Diver. Thanks to the authors' trademark rigorous methodology, the signature of the 'ONLY' reference works, this book reveals the incredible diversity of the Chronomaster models. It is intended both as an initiation for connoisseurs of exceptional watches and as a reference guide for collectors. This legendary watch will doubtless thus regain the place it deserves among the most desirable 1960s chronographs.