All Seiko lines › Seiko 5 Sports › SKX series
“Fifty Five Fathoms”
Seiko 5 Sports SKX series, 42.5 mm, 14.2 mm thick (4R36)
Collector nickname. Where the name comes from
8 versions of this watch are on Seiko's own sites right now, across 34 regions. Last checked Nov 13, 2026.
Estimated US price: About $335 to $400 from Seiko's US list price and its list prices in other countries, converted.
Retailers ask: $320 to $475 across 9 listings at 5 sellers, checked Nov 13, 2026. See the sellers
Black
Blue
Photos are Seiko's own, shown from Seiko's sites. Click a photo to jump to that version.
- Calibre
- 4R36
- Case diameter
- 42.5 mm
- Thickness
- 14.2 mm
- Lug to lug
- 46 mm
- Variants listed now
- 8
- Regions
- 34
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 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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 | HDB004 Also coded HDB004K1 | Not published | Not stated Clasp: Three-fold clasp with push button release 169 g | Stainless steel | Regular | 32 regions | 400 USD USA · Nov 13, 2026 | From 400.00 USD Teddy Baldassarre · 1 seller checked | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (37 sites) and its list prices
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.
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 | HDB005 Also coded HDB005K1 | Not published | Not stated Clasp: Three-fold clasp with push button release 169 g | Stainless steel | Regular | 32 regions | 400 USD USA · Nov 13, 2026 | Not seen in stock 1 seller checked | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (37 sites) and its list prices
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.
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 | SRPK99 Also coded SRPK99K1 | Black Seiko USA store tag | Not stated Clasp: Three-fold clasp with push button release 169 g | Stainless steel | Regular | 29 regions | 400 USD USA · Nov 13, 2026 | From 320.00 USD Long Island Watch · 3 sellers checked | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (35 sites) and its list prices
Buying options (3)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.
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 | SRPK97 Also coded SRPK97K1 | Blue Seiko USA store tag | Not stated 168 g | Stainless steel | Regular | 27 regions | 400 USD USA · Nov 13, 2026 | From 320.00 USD Long Island Watch · 3 sellers checked | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (33 sites) and its list prices
Buying options (3)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.
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 | HDB004J | Not published | Not stated 169 g | Stainless steel; case back: stainless steel and glass Translated from Seiko's regional page | Regular | 1 region Japan | 53,900 JPY Japan · Nov 13, 2026 about $335 in US dollars | From 320.00 USD Japan Select · 1 seller checked | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (1 site) and its list prices
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.
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 | HDB005J | Not published | Not stated 169 g | Stainless steel; case back: stainless steel and glass Translated from Seiko's regional page | Regular | 1 region Japan | 53,900 JPY Japan · Nov 13, 2026 about $335 in US dollars | From 320.00 USD Japan Select · 1 seller checked | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (1 site) and its list prices
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.
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 | SBSA259 | Not published | Not stated 169 g | Stainless steel; case back: stainless steel and glass Translated from Seiko's regional page | Regular | 1 region Japan | 53,900 JPY Japan · Nov 13, 2026 about $335 in US dollars | No seller matched yet | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (1 site) and its list prices
Buying options (0)No seller offer has been matched to this exact variant yet. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 | SBSA261 | Not published | Not stated 169 g | Stainless steel; case back: stainless steel and glass Translated from Seiko's regional page | Regular | 1 region Japan | 53,900 JPY Japan · Nov 13, 2026 about $335 in US dollars | No seller matched yet | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Where Seiko lists it (1 site) and its list prices
Buying options (0)No seller offer has been matched to this exact variant yet. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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.
| Seller | Version | Asking price | Checked |
|---|---|---|---|
| Japan Select | HDB004J | 320.00 USD | Nov 13, 2026 |
| Japan Select | HDB005J | 320.00 USD | Nov 13, 2026 |
| Long Island Watch | SRPK97 | 320.00 USD | Nov 13, 2026 |
| Long Island Watch | SRPK99 | 320.00 USD | Nov 13, 2026 |
| Seiko Boutique Ireland | SRPK97 | 429.00 EUR about $475 | Nov 13, 2026 |
| Seiko Boutique Ireland | SRPK99 | 429.00 EUR about $475 | Nov 13, 2026 |
| Seiko USA | SRPK97 | 400.00 USD | Nov 13, 2026 |
| Seiko USA | SRPK99 | 400.00 USD | Nov 13, 2026 |
| Teddy Baldassarre | HDB004 | 400.00 USD | Nov 13, 2026 |
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 | Automatic with manual winding | Seiko product page |
|---|---|---|
| Functions | Stop second hand function Day/Date display | Seiko product page |
| Power reserve / battery | Approx. 41 hours | Seiko product page |
| Water resistance | 10 bar | Seiko product page |
| Crystal | Curved Hardlex | Seiko product page |
| Lug width | 22 mm | Seiko product page |
| Seiko case codes | 4R36-16D0 | Seiko catalog data |
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. 12 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.
| “Fifty Five Fathoms” | Collector nickname. Source names HDB004, HDB005, SRPK99. “Seiko's Affordable "Fifty Five Fathoms" Dive Watch Gets a Striking Makeover” First given to the discontinued SNZH models. The source calls these the reborn version. | Gear Patrol read 2026-11-12 |
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Related lines
- Seiko 5 Sports SKX series, 42.5 mm, 13.9 mm thick (4R36)
Same calibre and diameter, different published case - “5KX” · Seiko 5 Sports SKX series, 42.5 mm, 13.4 mm thick (4R36)
Same calibre and diameter, different published case
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