1978 Seiko Turtle Diver (Ref. 6306-7001) "JDM"

The Seiko 6306-7001 is the Japanese Domestic Market (JDM) version of Seiko’s third-generation professional diver, produced from 1976 to 1988. A counterpart to the 6309-7049 made for the American market, the 6306-7001 is powered by a superior movement featuring hacking seconds and a higher jewel count—making it a favorite among collectors and enthusiasts alike.

Both variants share the same robust case dimensions: 45mm wide, 48mm lug-to-lug, and 13mm thick, with a 22mm lug width. The case itself is classic Seiko tool-watch design—circular brushing on the top, polished sides and caseback, and a strong mid-case line separating the surfaces. The screw-down crown at 4 o'clock ensures excellent water resistance and ergonomic functionality.

Notable features include a double-row knurled bezel for enhanced grip, a bold and highly legible handset designed for underwater visibility, and a day/date complication with quickset functionality. Altogether, the 6306-7001 offers a rugged, reliable, and function-forward design that has influenced Seiko's diver lineage for decades.

Culturally, this era of Seiko Divers holds a place in history—its sibling model was famously worn by Ed Harris in The Abyss, and Mick Jagger has been seen wearing his personal example. While most surviving examples show heavy wear from serious use, this particular piece remains in excellent, original condition—an increasingly rare find.