Seiko SRP777 'Turtle'
Ref. SRP777 · In production (variants)
- Case45 mm
- Thick13.4 mm
- Water res.200 m
- MovementAutomatic
- CrystalHardlex (Seiko mineral)
Overview
The Seiko SRP777 is a diver watch from the Prospex collection, part of the Seiko Turtle family. It has a 45 mm stainless steel case, 13.4 mm thick. Inside is a automatic movement (calibre 4R36) with 41 h of power reserve. You also get 200 m water resistance and a hardlex (seiko mineral) crystal.
Who it suits
- Wrists of roughly 18.1–20.0 cm (7.1–7.9 in), by our Watch Finder sizing guide
- Swimming, snorkelling and diving
Strengths
- 200 m water resistance
Trade-offs
- Hardlex (Seiko mineral) crystal scratches more easily than sapphire
- 41 h power reserve: it stops after about a day and a half off the wrist
Written by Watch.co from the published specs below. These are not owner reviews.
Full specifications
Case
| Case diameter | 45 mm | seikowatches.com · 23 Oct 2026 |
|---|---|---|
| Thickness | 13.4 mm | seikowatches.com · 23 Oct 2026 |
| Case material | Stainless steel | seikowatches.com · 23 Oct 2026 |
| Crystal | Hardlex (Seiko mineral) | seikowatches.com · 23 Oct 2026 |
| Water resistance | 200 m | seikowatches.com · 23 Oct 2026 |
Movement
| Movement type | Automatic | seikowatches.com · 23 Oct 2026 |
|---|---|---|
| Calibre | 4R36 | seikowatches.com · 23 Oct 2026 |
| Power reserve | 41 h | seikowatches.com · 23 Oct 2026 |
Strap / Bracelet
| Lug width | 22 mm | seikowatches.com · 23 Oct 2026 |
|---|
Other
| Production status | In production (variants) | seikowatches.com · 23 Oct 2026 |
|---|---|---|
| Style (our classification) | Diver | seikowatches.com · 23 Oct 2026 |
| Nickname | Turtle | our classification |
Specs are summarised in our own words from the brand's product page. Each row links its source and the date we checked it. Fields we haven't verified are left out rather than guessed.
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Questions about the Seiko SRP777
How big is the Seiko SRP777?
The case is 45 mm wide, 13.4 mm thick.
What movement does the Seiko SRP777 use?
It uses the 4R36 calibre, a automatic movement with 41 h of power reserve.
Can I swim with the Seiko SRP777?
Yes. It is rated to 200 m.
Will the Seiko SRP777 fit my wrist?
By our sizing guide it sits best on wrists of about 18.1–20.0 cm (7.1–7.9 in). Use the fit checker on this page to test your own wrist.
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