Since introducing Japan’s first diver’s watch in 1965, Seiko has built an unmatched heritage in professional dive watch design. The SPB455J1 marks a historic milestone in that story: released to celebrate the 100th anniversary of the Seiko brand, it is a direct evolution of the original 1965 reference that started it all — now with a 40 mm case, 300 metres of water resistance and a new generation in-house movement, while staying faithful to the proportions and aesthetic of the 1965 original. The charcoal-grey sunray dial with gold-tone accents gives this anniversary edition an immediately distinctive character that sets it apart from the standard black and blue variants in the same generation.

Reference SPB455J1 is a 40 mm stainless steel automatic diver’s watch, 13 mm in thickness with a lug-to-lug of 46.4 mm, fitted with a super-hard coating for scratch resistance. The charcoal-grey sunray dial carries gold-toned LumiBrite-coated hour markers and hands, with the date window positioned between four and five o’clock — colour-matched to the dial for a clean, symmetrical layout. At its heart beats the Seiko Calibre 6R55, an automatic movement with manual winding capability and a 72-hour power reserve. The curved sapphire crystal carries anti-reflective coating on the inner surface. The unidirectional rotating bezel carries a gold-toned LumiBrite diving scale. Water resistance is rated to 300 metres. The watch is supplied with a stainless steel three-fold bracelet with secure lock and diver’s extension, plus an additional fabric strap woven from recycled plastic bottles using the traditional Japanese Seichu technique.

This Seiko Prospex 1965 Heritage Diver’s 100th Anniversary Special Edition is in near mint condition and comes as a full set with the extra Seiko black nato strap.