53243, Prototype Blue Dial Bathy 50, Steel
A Mark 1 Bathy 50 with a very rare prototype blue dial. The Bathy 50 was the world’s first watch to display a dive time and depth readout. Yes, this watch is designed around one of the earliest wristwatch mechanical depth gauge complications. It is estimated that fewer than 1000 examples were ever produced. Far fewer survive today and this is the only blue dial known to the market, originally from a long-standing retired employee at Favre-Leuba in the 1960s.