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“Tuna”

Seiko Prospex Street Series diver's, 43.2 mm (4R35)

Collector nickname. Where the name comes from

4 versions of this watch are on Seiko's own sites right now, across 8 regions. Last checked Nov 13, 2026.

Estimated US price: About $550 to $630 from Seiko's US list price and its list prices in other countries, converted.
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
4R35
Case diameter
43.2 mm
Thickness
12.6 mm
Lug to lug
44 mm
Variants listed now
4
Regions
8

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.

PhotoReferenceColourStrap / braceletCaseEditionListed inSeiko list priceBuy
Seiko SRPG59SRPG59
Also coded SRPG59K1
Not publishedSilicone
104 g
Stainless steelSave the Ocean Special Edition5 regions550 USD
USA · Nov 13, 2026
Not seen in stock
1 seller checked
Where Seiko lists it (5 sites) and its list prices
Seiko siteListed asSeiko list priceChecked
AustraliaSRPG59850 AUD
IndonesiaSRPG59No price shown
Middle EastSRPG59540 (currency not shown)
PolandSRPG592,500 PLN
USASRPG59550 USD
Buying options (1)

Offers seen available at the last check come first, then by item price. Shipping, taxes and import charges are not included. Commission never affects the order.

Seller / sold referenceItem priceStock at last checkWarrantyChecked
Long Island Watch

Seller title: Seiko Prospex Save The Ocean, Special Edition Baby Tuna "Antarctica" Dive Watch #SRPG59
440.00 USDObserved unavailable at the recorded check; live stock unverifiedunknown
Seiko SRPH77SRPH77
Also coded SRPH77K1
Not publishedSilicone
104 g
Stainless steelSave the Ocean Special EditionSave the Ocean Özel Üretim4 regions
Australia, Hungary, Poland, Türkiye
850 AUD
Australia · Nov 13, 2026
about $630 in US dollars
Not seen in stock
1 seller checked
Where Seiko lists it (4 sites) and its list prices
Seiko siteListed asSeiko list priceChecked
AustraliaSRPH77850 AUD
HungarySRPH77K1No price shown
PolandSRPH772,500 PLN
TürkiyeSRPH7732,395 TRY
Buying options (1)

Offers seen available at the last check come first, then by item price. Shipping, taxes and import charges are not included. Commission never affects the order.

Seller / sold referenceItem priceStock at last checkWarrantyChecked
Long Island Watch

Seller title: Seiko Prospex Baby Tuna "Save The Ocean Antarctica” Penguin Dial Dive Watch #SRPH77
440.00 USDObserved unavailable at the recorded check; live stock unverifiedunknown
Seiko SRPF83SRPF83
Also coded SRPF83K1
Not publishedSilicone
105 g
Stainless steelRegular3 regions
Australia, India, Indonesia
850 AUD
Australia · Nov 13, 2026
about $580 in US dollars
No seller matched yet
Where Seiko lists it (3 sites) and its list prices
Seiko siteListed asSeiko list priceChecked
AustraliaSRPF83850 AUD
IndiaSRPF83No price shown
IndonesiaSRPF83No price shown
Buying options (0)

No seller offer has been matched to this exact variant yet.

Seiko SRPF81SRPF81
Also coded SRPF81K1
Not publishedSilicone
105 g
Stainless steelRegular2 regions
Australia, India
850 AUD
Australia · Nov 13, 2026
about $580 in US dollars
No seller matched yet
Where Seiko lists it (2 sites) and its list prices
Seiko siteListed asSeiko list priceChecked
AustraliaSRPF81850 AUD
IndiaSRPF81No price shown
Buying 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

MovementAutomatic with manual windingSeiko product page
FunctionsStop second hand function Date displaySeiko product page
Power reserve / batteryApprox. 41 hoursSeiko product page
Water resistance200m / 660ft diver'sSeiko product page
CrystalHardlexSeiko product page
Lug width20 mmSeiko product page
Seiko case codes4R35-04L0, 4R35-04Z0Seiko catalog data

Why these share a page

Every version here is published by Seiko with calibre 4R35 and either the same Seiko case code or the same case size. 8 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 SRPF81K1.
“Anyway, the SRPF81K1 (81 from here out) is an all-together stylized take on the Tuna in a gorgeous deep blue and champagne gold colorway.”
Worn & Wound
read 2026-11-12

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