All Seiko lines › Prospex › Sea
“Tuna”
Seiko Prospex Sea, 47.7 mm (7C46)
Collector nickname. Where the name comes from
2 versions of this watch are on Seiko's own sites right now, across 12 regions. Last checked Nov 13, 2026.
Estimated US price: About $1,650 to $1,705, converted from Seiko's list prices in AUD, EUR, HKD and more.
Retailers ask: no retailer listing matched yet.
Photos are Seiko's own, shown from Seiko's sites. Click a photo to jump to that version.
- Calibre
- 7C46
- Case diameter
- 47.7 mm
- Thickness
- 14.1 mm
- Lug to lug
- 46.7 mm
- Variants listed now
- 2
- Regions
- 12
Listed means the watch was on an official Seiko regional site or store at the last check. It does not mean it is in stock, and it does not tell us whether Seiko is still making it.
Versions listed now
Same case and movement in every row. What changes is the colour, the strap or bracelet, the finish and where Seiko sells it. Seiko's spec sheets don't state dial colour, so a colour appears only where Seiko's US store tags one.
| Photo | Reference | Colour | Strap / bracelet | Case | Edition | Listed in | Seiko list price | Buy | ||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 | S23629 Also coded S23629J1 | Not published | Silicone 129 g | Stainless steel (super hard coating) | Regular | 10 regions | 1,700 EUR Portugal · Nov 13, 2026 about $1,650 in US dollars | No seller matched yet | ||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (10 sites) and its list prices
Buying options (0)No seller offer has been matched to this exact variant yet. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
 | S23633 Also coded S23633J1 | Not published | Not stated Clasp: Three-fold clasp with secure lock & push button release, solid & slide adjuster 200 g | Stainless steel (super hard coating) | Regular | 4 regions Australia, Indonesia, Latin America, Middle East | 2,500 AUD Australia · Nov 13, 2026 about $1,705 in US dollars | No seller matched yet | ||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (4 sites) and its list pricesBuying options (0)No seller offer has been matched to this exact variant yet. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Where to buy
No retailer listing has been matched to a version on this line yet.
Estimated US prices use Seiko's US list price where there is one. Otherwise they are the middle of Seiko's list prices in other countries, converted at rates dated Nov 12, 2026 from ExchangeRate-API (free open endpoint). Those list prices include each country's sales tax, so a converted figure usually runs higher than a US price would. Retailer prices are asking prices on the date shown, not sold prices, and leave out shipping, tax and import charges.
The build
| Movement | Quartz | Seiko product page |
|---|---|---|
| Functions | Day/Date display | Seiko product page |
| Power reserve / battery | Approx. 5 years | Seiko product page |
| Water resistance | 300m / 1000ft for saturation diving | Seiko product page |
| Crystal | Curved sapphire crystal Some variants are published as: Sapphire crystal | Seiko product page |
| Lug width | 22 mm | Seiko product page |
| Seiko case codes | 7C46-0AN0 | Seiko catalog data |
Why these share a page
Every version here is published by Seiko with calibre 7C46 and either the same Seiko case code or the same case size. 4 reference codes lead to this page.
What people call it
A name is shown only where a source ties it to a reference on this page. Collector nicknames are not Seiko's names unless the row says so.
| “Tuna” | Collector nickname. Source names S23629. “The S23631 and the S23629 are the newest entries in Seiko’s long line of Tuna cased watches, with a distinctive, love it or hate it shroud surrounding the bezel, creating a hockey puck-like case shape.” | Worn & Wound read 2026-11-12 |
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