All Seiko lines › Prospex › Sea
“Tuna”
Seiko Prospex Sea, 49.4 mm (7C46)
Collector nickname. Where the name comes from
2 versions of this watch are on Seiko's own sites right now, across 3 regions. Last checked Nov 13, 2026.
Estimated US price: About $2,645 to $3,270, converted from Seiko's list prices in INR, THB.
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
- 49.4 mm
- Thickness
- 15.3 mm
- Lug to lug
- 49.4 mm
- Variants listed now
- 2
- Regions
- 3
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 |
|---|---|---|---|---|---|---|---|---|
 | S23627 Also coded S23627J1 | Not published | Silicone Translated from Seiko's regional page | Keramik / titanium (lapisan keras) dengan bezel baja tahan karat Seiko's regional wording | Regular | 3 regions India, Indonesia, Thailand | 285,000 INR India · Nov 13, 2026 about $3,270 in US dollars | No seller matched yet |
Where Seiko lists it (3 sites) and its list pricesBuying options (0)No seller offer has been matched to this exact variant yet. | ||||||||
 | S23626 Also coded S23626J1 | Not published | Silicone Translated from Seiko's regional page | Not stated | Seiko Prosepx The 1978 Quartz Saturation Diver’s Re-creation Limited Edition | 2 regions Indonesia, Thailand | 89,600 THB Thailand · Nov 13, 2026 about $2,645 in US dollars | No seller matched yet |
Where Seiko lists it (2 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 | Kuarsa | Seiko product page |
|---|---|---|
| Functions | Tampilan Hari / Tanggal | Seiko product page |
| Water resistance | 1000m / 3300ft untuk penyelaman saturasi | Seiko product page |
| Crystal | Safir | Seiko product page |
| Lug width | 22 mm | Seiko product page |
| Seiko case codes | 7C46-0AL0, 7C46-0AM0 | 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 S23626. “The Seiko Tuna is no shrinking violet; however, with a lightweight quartz movement and a titanium core it doesn’t feel unsteady or overbearing.” The source is a hands-on of S23626; the sentence quoted does not repeat the reference. | Time+Tide read 2026-11-12 |
|---|
Related lines
- “Tuna” · Seiko Prospex Marinemaster Professional, 49.4 mm (7C46)
Same calibre and diameter, different published case
Holden's Watch Desk is an independent catalog. It is not affiliated with, sponsored by or endorsed by Seiko. Seiko and its model names are trademarks of their owners, and the product photos are Seiko's, shown from Seiko's own sites to identify each watch. To report a mistake or ask for something to be removed, email holden@holdenswatchdesk.com.