Rolex officially launched the first version of the Sea Dweller reference 1665 in 1967. The highly technical diving watch was specifically engineered to sustain extreme depths which the world-famous COMEX divers would reach while working on gas and oil rigs. The helium escape valve was a revolution by allowing the accumulated helium to be released out of the case without harming the movement or dislocating the plexiglass. The reference 1665 was first produced in rather conservative numbers and offered a 500m water resistance. The now iconic Double Red variant followed suit, bearing the ‘SEA-DWELLER’ and ‘SUBMARINER 2000’ text spread on two red lines. Collectors have identified four main evolutions until 1977, the year Rolex introduced ‘Great White’ dials.
The present Rolex 1665 Double Red, dated from 1975, bears a Mark IV dial with a larger font ‘2000ft = 610m’ script, a closed 6 for the depth rate and a wide oval base to the sharper coronet. The present dial displays a striking patina to its indexes with matching hands and a period correct silver date disc. Another Mark IV feature, the full case number is engraved to the inside case back as opposed to the sole last three digits until 1974.