Grand Seiko SBGW306
Ref. SBGW306 · In production
- Case36.5 mm
- Thick11.7 mm
- Lug-to-lug42.7 mm
- Water res.100 m
- MovementManual-wind
- CrystalSapphire
Overview
The Grand Seiko SBGW306 is a sports watch from the Heritage collection. It has a 36.5 mm gold case, 11.7 mm thick, 42.7 mm from lug to lug. Inside is a manual-wind movement (calibre 9S64) with 72 h of power reserve. You also get 100 m water resistance and a sapphire crystal.
Who it suits
- Wrists of roughly 14.5–16.4 cm (5.7–6.4 in), by our Watch Finder sizing guide
- Everyday wear including swimming
- People who enjoy seeing a mechanical movement at work
Strengths
- Sapphire crystal resists scratches
- 72 h power reserve survives a weekend off the wrist
- Compact 42.7 mm lug-to-lug suits smaller wrists
- Display caseback shows the movement
Written by Watch.co from the published specs below. These are not owner reviews.
Full specifications
Case
| Case diameter | 36.5 mm | grand-seiko.com · 23 Oct 2026 |
|---|---|---|
| Thickness | 11.7 mm | grand-seiko.com · 23 Oct 2026 |
| Lug-to-lug | 42.7 mm | grand-seiko.com · 23 Oct 2026 |
| Case material | Gold | grand-seiko.com · 23 Oct 2026 |
| Crystal | Sapphire | grand-seiko.com · 23 Oct 2026 |
| Anti-reflective coating | Anti-reflective coating on inner surface | grand-seiko.com · 23 Oct 2026 |
| Caseback | Display (see-through) | grand-seiko.com · 23 Oct 2026 |
| Water resistance | 100 m | grand-seiko.com · 23 Oct 2026 |
| Magnetic resistance | 4,800 A/m | grand-seiko.com · 23 Oct 2026 |
Dial
| Date | No date | our classification |
|---|
Movement
| Movement type | Manual-wind | grand-seiko.com · 23 Oct 2026 |
|---|---|---|
| Calibre | 9S64 | grand-seiko.com · 23 Oct 2026 |
| Made in-house | Yes | grand-seiko.com · 23 Oct 2026 |
| Power reserve | 72 h | grand-seiko.com · 23 Oct 2026 |
| Hand-winding | Yes | grand-seiko.com · 23 Oct 2026 |
Strap / Bracelet
| Lug width | 18 mm | grand-seiko.com · 23 Oct 2026 |
|---|
Other
| US list price (MSRP) | $17,900 | grand-seiko.com · 23 Oct 2026 |
|---|---|---|
| Production status | In production | grand-seiko.com · 23 Oct 2026 |
| Style (our classification) | Sports | 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 Grand Seiko SBGW306
How big is the Grand Seiko SBGW306?
The case is 36.5 mm wide, 11.7 mm thick and 42.7 mm from lug to lug.
What movement does the Grand Seiko SBGW306 use?
It uses the 9S64 calibre, a manual-wind movement with 72 h of power reserve.
Can I swim with the Grand Seiko SBGW306?
Yes. It is rated to 100 m.
Does the Grand Seiko SBGW306 have a date?
No, it has no date display.
How much is the Grand Seiko SBGW306?
The US list price was $17,900 on grand-seiko.com when we checked on 23 Oct 2026. Prices change, so check before you buy.
Will the Grand Seiko SBGW306 fit my wrist?
By our sizing guide it sits best on wrists of about 14.5–16.4 cm (5.7–6.4 in). Use the fit checker on this page to test your own wrist.
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