
Seiko
Seiko's upgraded automatic caliber offering a substantial 70-hour power reserve, nearly double the 4R35 it replaces in higher-end Presage and Prospex models. The extended reserve is achieved through a longer mainspring while maintaining the same 21,600 vph beat rate. Accuracy is tightened to -15/+25 seconds per day compared to the 4R35's wider tolerance. Represents Seiko's push to compete with Swiss movements offering 80-hour reserves.
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Prospex Sea collection · 33 watches
The market
The forum market
Browse forum listings and their asking prices. Market+ adds medians with their sample sizes and the weekly trend.
Seiko on the secondhand market
+10.4%
2026 so far · +5.9% to +17.2% · 91 matched watches
In line with the index
Divers as a group: +6.5% · 340 matched watches
Year-by-year readings →The connection engine
The community take
Owners widely praise the Seiko Prospex Sea for its excellent lume, robust build, and value, with many highlighting the comfortable 4 o'clock crown and reliable movements. Reviewers note impressive case finishing and attractive dials, with specific models lauded for their gradient blue designs and smooth bezel actions. Accuracy figures vary, with one owner reporting +9 seconds/day after demagnetization, while others find the watches to be good first "proper" watches. Some owners find the stock rubber straps uncomfortable or the overall size substantial on smaller wrists. On balance, owners and reviewers rate the Seiko Prospex Sea highly for its combination of strong dive watch functionality and appealing design at its price point.
On real wrists
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The paper trail
In collections
The matchups people make with the Seiko Prospex Sea most: open one to see it side by side.
The discussion