Seiko Vintage Watch - The Turtle 6306-7001: The beast from Japan

March 30, 2023 Joshua Grillet

The story of Seiko's legendary vintage diver's watch, the Turtle Diver 6306-7001

In the world of vintage Seiko divers, some are myths and become as desirable as they are difficult to find for “ Seikoholics ”.
The Turtle 6306 clearly falls into this category.

Between 1965 and 1975, Seiko brilliantly designed and produced three generations of ISO 150m certified dive watches. In chronological order, the 62MAS , the 6105-8000 /9 and the 6105-8010 /9. In 1975, Seiko commissioned a young engineer named Ikuo Tokunaga to create the new Diver 150m.

seiko diver 6217 6105 lumeville vintage watch

It was in 1976 that Seiko released the replacement for the 6105, designed in two versions. One for the Japanese market and the other for the foreign market . This last international variant, the 6309, was equipped with a 17-jewel 6309A automatic movement and a bilingual day display adapted to the geographic target, while the version reserved for the Japanese market (JDM), the 6306, was equipped with A more advanced movement, the 6306A with 21 jewels , a stop seconds system and the day display in English/Japanese kanji .
The Japanese versions of Seiko models often have more advanced movements than the export versions, like on the Pogue for example, 21 jewels in the JDM version compared to 17 for the export version. Customs taxation problem or simple vanity for its historic customers?

The 6306 had a fairly short lifespan as it was only produced from 1976 to 1981 . Seiko kept the 6309 in the catalog until it was replaced by the Diver 7002 in 1988.

Both versions were popular with the US Army , like its ancestor the 6105 (which was much more expensive), and quickly became real workhorses.

seiko diver turtle 6306-7001 lumeville vintage watch

Analysis of the legendary vintage Seiko Turtle Diver 6306-7001 diving watch

Here is the nugget that I unearthed, a 6306-7001 from January 1969 in rather good cosmetic condition. At first glance, the glass and bezel have a few scratches and the movement runs very poorly. Additionally there is a little play in the bezel.

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

We open the beast and we find a movement in good condition but very dirty.

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

After complete dismantling of the trim parts we found a lot of dirt and rust. This granny didn't spend her life at the bottom of a drawer!

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

Seiko 6306 review: disassembly and cleaning

Let’s disassemble the movement.

This one is very dirty, the oils are completely erased. A good revision won't do it any harm. Maybe this is his first revision?

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

Here we can see its stop seconds system. A lever connected to the winding stem touches the axis of the escape wheel when the watch is set to the time. This has the effect of stopping the movement, the second hand remains fixed for more precise time setting.

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch Cleaning vibrasonic movement elma watchmaker

Overhaul of the Seiko 6306: reassembly and oiling

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

The movement is wound without its automatic system. It will be replaced just before closing the back of the watch to allow better access to the balance wheel settings.

Seiko Turtle Diver 6306-7001: glass replacement

A new glass is placed on the “L” joint then held in force by a clipped strapping.

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

The bezel can be replaced with a new gasket, which has the effect of eliminating play. The dial/hands/movement assembly is placed in the case, as well as the winding stem and the automatic system. A new back seal is installed, you can close the screwed back and enjoy a precise watch again!

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

Seiko Turtle Diver 6306-7001: Conclusion

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

This diver is iconic and Seiko has understood this by reissuing it in an infinite number of versions.

Its connection to the history of Seiko, diving and the army make it a must have for collectors. I admit to keeping one jealously in my collection.

To dress it up with care, you can equip it with a nato strap, a vintage Tropic or a reproduction. The ideal would be to find his original GL831 but these bracelets have aged badly and few have survived. These bracelets have been reissued by Seiko and by Uncle Seiko.

Seiko diver jdm Turtle 6306-7001 lumeville vintage watch

You can find this superb copy in the online store and I congratulate its next owner in advance!