Seiko was founded in Tokyo in 1881 and has grown into one of the few truly integrated watch manufacturers in the world — designing, developing and producing its own movements from the ground up. The Prospex collection carries the brand's most serious tool watch credentials, tracing its roots to 1965 when Seiko introduced Japan's first diver's watch. The 1968 Heritage line within Prospex pays direct tribute to a landmark model from that era, reinterpreting its distinctive case architecture with fully contemporary specifications. The HBC002J1 marks a significant milestone: it is the first Seiko mechanical diver's watch to feature a built-in GMT complication.

Reference HBC002J1 is a 42 mm stainless steel GMT diver's watch built on the design language of Seiko's iconic 1968 reference, with mirror-finished case sides that give it an immediately recognisable character. The case carries a super-hard coating for scratch resistance and measures 13.3 mm in thickness. The "Oceanic Black" dial is nicely structured for underwater legibility: oversized hour plots and faceted hands are heavily coated in Seiko's LumiBrite, while a gold-tone 24-hour GMT hand sits in clear contrast against the dark background, allowing a second time zone to be read at a glance. A date window sits discreetly between four and five o'clock. At its heart beats the Seiko Calibre 6R54, the brand's in-house automatic GMT movement with manual winding capability, running at 21,600 vph with 24 jewels and a 72-hour power reserve — serious specifications at this price point. The flat sapphire crystal carries an anti-reflective coating on the inner surface. The unidirectional rotating bezel features a black ceramic insert with a knurled edge for easy grip even with diving gloves. Water resistance is rated to 300 metres. The watch is fitted on a three-link stainless steel bracelet with a tool-free slide-adjuster clasp offering six-step micro-adjustment over a total range of approximately 15 mm.

This Seiko 1968 Heritage Diver's is in mint condition and comes as a full set.