Seiko J13046
The Seiko Cronos J13046 is a 35mm hand-wound watch made by Daini Seikosha around 1962, and the Water 50 Proof member of the Cronos Waterproof family. Seiko had launched that family in 1959 as its first watch with a declared 50 metre rating, sealed with a two-part caseback. The J13046 is the version whose dial reads Water 50 Proof, above Diashock 21 Jewels, and the caseback carries the seahorse Seiko used in this period for hand-wound waterproof models. Inside is the hand-wound 21-jewel Daini Cronos movement, rarely stamped with a number, which repairers generally identify as the 54-00-2, or 54A, though Seiko has not confirmed it. It was rated for swimming and winter sport rather than diving, and it predates the 62MAS, Seiko's first true dive watch, by several years.
| Caliber | Cronos 21 jewels (Daini) |
|---|---|
| Years | 1962 to present |
| Line | Cronos |
| Case size | 35mm |
| Lug width | 18mm |
| Crystal | Acrylic |
| Water resistance | 50m |
| Factory | Daini |
What does the seahorse on the caseback mean?
Seiko used the seahorse emblem during this era to denote manual-wind watches with water resistance. Automatic models typically received a dolphin engraving instead.
Is the Cronos J13046 a dive watch?
While collectors sometimes refer to it as a "pre-diver," the J13046 was rated to 50 meters and lacks a rotating bezel. It was designed for active everyday use like swimming rather than scuba diving, preceding Seiko's first true dive watch, the 62MAS.
What movement is in the Seiko Cronos J13046?
A hand-wound 21-jewel Cronos caliber made by Daini Seikosha, with Diashock shock protection and no date. The movement is rarely stamped with a number, but repairers generally identify it as the 54-00-2, written 54A in Seiko's later system, which is likely but not confirmed by Seiko documentation.
