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Seiko Prospex 1965 Heritage Diver's PADI Special Edition 40mm Mens Watch Green
Ref. SPB501J1
Sits in Seiko’s upper tier here — more premium than three quarters of the Seiko watches we list, which start at £110.
Price range £110 to £3,550 across 168 Seiko watches in stock.The 62MAS — Japan's first diver's watch, built in 1965 and tough enough to accompany the Japanese Antarctic Research Expedition four separate times, then later carried to the North Pole, the South Pole and Everest — is the direct ancestor here. This PADI Special Edition, announced in June 2025, sits alongside the Samurai SRPL53 as one of a pair of simultaneous PADI releases, and the two are more different than they might appear: the SPB501J1 carries a curved sapphire crystal where the Samurai uses Hardlex mineral glass, and its 6R55 movement offers a 72-hour power reserve against the Samurai's 41 hours. The calibre also appears in the King Seiko line, which is where Seiko puts movements it considers worth showing off. At 40mm with a 46.4mm lug-to-lug span, the case sits compactly for a 300-metre diver, and 13mm of thickness means it passes under a shirt cuff without negotiation. The gradient emerald dial depicts the ocean surface as seen from below, light breaking through — which explains the colour shifting rather than being flat — and the PADI ocean pattern is woven into it rather than applied as a label. The clasp adjusts across roughly 15mm in 2.5mm increments, enough to account for a wetsuit sleeve without resorting to a different hole. The second strap, made from discarded fishing nets using a Japanese weaving technique traditionally reserved for kimono obi belts, is a detail that repays a closer look.
- Reference
- SPB501J1
- Brand
- Seiko
- Collection
- Prospex
- Case size
- 40mm
- Case thickness
- 13mm
- Case material
- Stainless steel
- Dial
- Green
- Crystal
- Sapphire
- Bezel
- Unidirectional rotating
- Movement
- Automatic
- Calibre
- 6R55
- Functions
- Date
- Water resistance
- 300m
- Bracelet / strap
- Stainless steel bracelet
- Strap colour
- Silver
- Clasp
- Deployant clasp
- Lume
- LumiBrite
- Retailer
- Goldsmiths
Additional specifications
- Lug-to-lug
- 46.4mm
Learn more about Seiko
Kintaro Hattori opened a watch and clock shop in Tokyo in 1881, aged twenty-one, and began manufacturing under the name Seikosha — roughly, house of exquisite workmanship — in 1892. The Seiko name appeared on watches from 1924.
The company's significance is that it broke the Swiss monopoly twice. First on precision: Seiko was appointed official timekeeper of the 1964 Tokyo Olympics and built the quartz chronometers and printing timers to do it, and in the 1960s its movements placed highly at the Neuchâtel and Geneva observatory trials against the best Swiss houses.
Then on technology. On Christmas Day 1969 Seiko released the Astron, the world's first quartz wristwatch, accurate to five seconds a month where mechanical watches managed that per day. The consequences for Switzerland were catastrophic — employment in the Swiss industry fell by roughly two-thirds over the following decade. Seiko deliberately did not enforce its quartz patents, allowing the technology to spread.
The same year it produced the 6139, among the first automatic chronographs, and it has since introduced Kinetic, Spring Drive — a hybrid regulating a mechanical mainspring electronically, giving a perfectly gliding seconds hand — and its own dive and field lines.
Seiko remains fully vertically integrated, making its own hairsprings, quartz crystals, and even the Zaratsu-polished cases, at price points from under a hundred pounds upward.
- 1881
- Kintaro Hattori opens his Tokyo shop.
- 1924
- The first watches carry the Seiko name.
- 1964
- Official timekeeper of the Tokyo Olympics.
- 1969
- The Astron becomes the first quartz wristwatch.
- 1999
- Spring Drive enters production.
Also in 7 collections
This watch appears in the Seiko Prospex range (32), Stainless Steel Watches (2,833), Automatic Watches (1,417), Sports Watches (667), Dive Watches (486), Green Dial Watches (392) and Watch Price Drops (293).
Temporarily out of stock
Mappin & Webb is not currently taking orders for this reference. Last listed as available on 26 September 2026. Stock is checked nightly and this page updates when it returns.
What the specifications mean
A mechanical watch built to be worn hard and got wet.
Strengths
- 300m water resistance, rated for actual diving
- 40mm suits most wrists
- 46.4mm lug-to-lug keeps the 40mm case wearable
- Sapphire crystal, which resists scratching
- Luminous hands and markers for low light
Price history
This watch is currently at its lowest recorded price. It reached £1,500 on 13 August. Prices are checked every day, and we record any changes.
Seiko Prospex 1965 Heritage Diver's alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification | SPB501J1 | T1454079705702 | H77455330 |
|---|---|---|---|
| Price | £1,050 | £960 | £915 |
| Case size | 40mm | 41mm | 41mm |
| Water resistance | 300m | 300m | 300m |
| Movement | Automatic | Automatic | Automatic |
| Strap | Stainless steel bracelet | Rubber strap | Rubber strap |
| Power reserve | — | 80 hours | 80 hours |
| This watch | Closely matched |
|
Your new watch
Frequently asked questions, and things you should know about this watch
Can I swim with it?
Yes. At 300m it is rated for swimming, snorkelling and recreational diving.
Water resistance explainedWill the glass scratch?
Unlikely. Sapphire is second only to diamond in hardness and shrugs off everyday marking.
Sapphire, mineral and acrylic comparedDoes it need a battery?
No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.
Quartz, automatic and solar comparedWill it fit my wrist?
Lug-to-lug is 46.4mm, which suits wrists from roughly 16cm (6¼ inches) upward.
Lug-to-lug decides fit more than case diameter does.
How to size a watch to your wristIs it a men's or women's watch?
Listed as men's, though at 40mm it sits in the range that suits anyone.
Has the price changed recently?
It's currently at its lowest recorded price since we began tracking it. It's ranged between £1,050 and £1,500, today it's £1,050.
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