Seiko Prospex 1965 Heritage Diver's PADI Special Edition 40mm Mens Watch Green

Ref. SPB501J1

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

Case size

40mm

Case thickness

13mm

Case material

Stainless steel

Case shape

Square

Dial

Green

Crystal

Sapphire

Movement

Automatic

Calibre

6R55

Functions

Date

Water resistance

300m

Bracelet / strap

Stainless steel bracelet

Strap colour

Silver

Clasp

Deployant clasp

Lume

LumiBrite

Retailer

Goldsmiths