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“Turtle”

Seiko Prospex Sea diver's, 45 mm, 13.4 mm thick (4R36)

Collector nickname. Where the name comes from

21 versions of this watch are on Seiko's own sites right now, across 29 regions. Last checked Nov 13, 2026.

Estimated US price: About $340 to $680 from Seiko's US list price and its list prices in other countries, converted.
Retailers ask: $420 to $460 across 3 listings at 2 sellers, checked Nov 13, 2026. See the sellers

Photos are Seiko's own, shown from Seiko's sites. Click a photo to jump to that version.

Calibre

4R36

Case diameter

45 mm

Thickness

13.4 mm

Lug to lug

47.7 mm

Variants listed now

21

Regions

29

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.

Where to buy

Asking prices for new watches at the last check. Each was in stock at that check, but stock moves, and shipping, tax and import charges are not included. Each reference links to the seller's page.

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

Why these share a page

Every version here is published by Seiko with calibre 4R36 and either the same Seiko case code or the same case size. 45 reference codes lead to this page.

Seiko publishes no lug-to-lug for these versions: SRP773, SRP775, SRP777, SRP779, SRP789, SRPA21, SRPC23, SRPC25, SRPC49, SRPC91, SRPD11, SRPE89, SRPE91, SRPE93, SRPE95, SRPE99, SRPF13, SRPF15. They are on this page because the calibre, diameter and thickness match.

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.

Related lines

• “King Turtle” · Seiko Prospex Sea diver's, 45 mm, 13.2 mm thick (4R36)
  Same calibre and diameter, different published case
• “Turtle” · Seiko Prospex Sea diver's, 45 mm, 13 mm thick (4R36)
  Same calibre and diameter, different published case

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