SOLD: SEIKO Automatic Diver 6309-7040 SOXA Sharkhunter

Watch is SOLD.

After finishing the Orange SOXA mod for my friend, I planned a second SOXA project for myself. I chose the DOXA SUB750T Sharkhunter as reference. The SUB750T Sharkhunter is reissue of the original Sharkhunter from 1967, which was worn by Jacques-Yves Cousteau, the famous French naval officer and marine explorer.

▲ DOXA SUB750T Sharkhunter. Image taken from DOXA website: http://www.doxawatches.com.

The base for modification is a SEIKO 6309-7040 from 1980s in fair condition. 6309 cushion case is a nice match for the DOXA tonneau case. It is all-original but some parts must go.

▲ SEIKO 6309-7040.

As usual, watch was stripped down to pieces and every parts were cleaned. Some parts were replaced. The original chapter ring was replaced by SOXA chrome chapter ring. Crystal gasket was replaced with a new one. Original crystal was replaced by domed sapphire with AR coating on the underside.

▲ Cleaned cushion cased in exploded view.

The best part of the modification is the power train. Instead of using the original SEIKO 6309A movement, I chose its JDM sibling, SEIKO 6306A with hack feature and Kanji day wheel. The hard-to-find 6306A movement was supplied by my friend, Kucimo Jahja. It was serviced by SEIKO technician and in very good condition. Runs in a shake and only loses 1 second per day on its first day inside the SOXA case.

▲ Power train of the Black SOXA, a JDM SEIKO 6306A movement.

▲ SOXA dial and hands on the 6306A movement.

The original crown was badly scratched. When I dismantled the crown-stem assembly, it turned out that the thread on male stem was broken too. So I replaced the crown with a genuine SEIKO NOS 6309 crown complete with new crown gasket inside. The male stem was also replaced with a used 6309 male stem from my parts inventory.

▲ Front: NOS 6309 crown and replacement male stem.

All parts assembled. A 22 mm solid Anvil bracelet with curved end was added as the final touch. The combination between domed sapphire and chrome chapter ring create illusion as if the dial is floating inside the case. I tried in vain to capture this effect using the camera. It looks more beautiful in person.