ROLEX SEA-DWELLER REF. 1665 “DOUBLE RED”

Brand

Model

Reference number

Year of production

Serial range

Case material

Case diameter

Dial

Helium Escape Valve

Water resistance

Movement

Bracelet

Clasp

Box

Papers

Condition

Signed

Description

Rolex

Sea-Dweller “Double Red” Patent Pending Mark II

1665

1967

2.2 million serial range

Stainless steel

40 mm

Matte black Double Red Mark II with tropical brown aging

Yes

2000 ft / 610 m

Automatic, Rolex calibre 1570

Stainless steel Oyster bracelet

Oyster folding clasp “Patent Pending”

No

No

Very good

Dial, case, movement and bracelet signed

This Rolex Sea-Dweller reference 1665 “Double Red” Patent Pending Mark II, bearing a 2.2 million serial number from 1967, belongs to the earliest and most important phase of Sea-Dweller production. It features the externally engraved “Patent Pending” caseback, preceding the official helium escape valve patent registration — a detail highly prized by collectors.

The Mark II dial displays the characteristic two red lines “SEA-DWELLER / SUBMARINER 2000,” consistent with early 1967 production. Particularly noteworthy is the attractive tropical aging, as the matte black surface has evolved into a rich and even brown tone — one of the most desirable traits in vintage Rolex collecting. The tritium markers exhibit a uniform and period-correct patina.

The robust 40 mm Oyster case incorporates the helium escape valve, engineered for professional saturation diving to depths of 2000 feet. Powering the watch is the correct Rolex calibre 1570 automatic movement, renowned for durability and precision.

An historically significant and highly collectible early Sea-Dweller, further enhanced by its tropical dial and Patent Pending caseback, representing a milestone in the evolution of professional Rolex dive watches.