Editorial
The SPB143J1 is Seiko's most faithful reproduction of the 1965 Professional Diver, the watch that started Japanese dive watchmaking. At 40.5mm it wears closer to the original than the Turtle, and the internal crown-operated bezel keeps the case clean. If you want the actual story of Seiko dive watches on your wrist, this is the reference to buy.
In 1965, Seiko released Japan's first purpose-built dive watch, a 200m-rated tool with an internal rotating bezel operated by the crown rather than an external grip. That design choice was practical: no bezel to snag on a wetsuit, no risk of accidental rotation. The SPB143J1, introduced in 2020, recreates that watch with period-correct proportions and a domed crystal that echoes the original acrylic.
Where the first-generation 6R15 movement topped out at 50 hours, Seiko upgraded the reproduction to the 6R35 with a 70-hour power reserve. The result is a watch that reads as a vintage piece but asks nothing of you in terms of daily winding discipline.
The crown-operated bezel is a period-correct feature that modern buyers sometimes find frustrating: you cannot spin it quickly the way you would a traditional external bezel, and you need to pull the crown to the correct position before adjusting. The domed crystal looks right but scratches more visibly than a flat sapphire under the same conditions. The lug width is 20mm but the short lug-to-lug and curved lugs mean some third-party straps that measure correctly will still sit poorly.
The "J1" suffix denotes Japanese domestic production, which is worth confirming when buying used, since the SPB143 designation also covers regional variants with minor dial differences. Finally, the warm white "ivory" dial reads distinctly yellow under some lighting, which is authentic to the vintage reference but can surprise buyers who expect a neutral cream.
