The watch is in excellent pre-owned condition, with a new custom Diver's Dial and Chapter Ring in a deep Burgundy colour, new custom 'MarineMaster' Hands, a very smart new Black & Silver 'Submariner' bezel insert, a new scratch-resistant Mineral Crystal, and a brand new aftermarket Seiko 'Accordion' Rubber diver's strap.  

This iconic Scuba Diver's watch has a large dual-finish steel case, which has been expertly polished and rebrushed, and looks superb. The Japanese produced Seiko 17 Jewel Automatic movement has been Fully Serviced and regulated, and is running beautifully, keeping accurate time.  I've used a modern luminous treatment on the Hands and Markers, and they glow beautifully after exposure to light (and it lasts for a while, which is a nice bonus on a redialled watch). The watch also has a 'Quickset' Day & Date window at the 3 o'clock position.  I'll also include a Seiko instruction manual (in PDF form, so you can print it, or save it to your computer).

Please read on.

Dial/Hands  New custom Dial, using a classic Swiss design Scuba Diver's style, in a distinctive deep Burgundy, with large black/white/black triple-baton indices. The dial is signed 'SEIKO, AUTOMATIC' to the left upper section, and 'PROFESSIONAL, WATER150MPROOF, Suwa symbol' to the right lower section. There is a printed Dolphin logo to the lower left. The triple-baton markers are larger at 6, 9 and 12, with a partial 'gunsight' inner section. There's a 'Quickset' Day & Date window at 3 o'clock (the Calendar can be adjusted to display the Day in English or Arabic.  The Days are displayed in Black, except on Sunday, which is printed in a contrasting Red (if you opt for the Arabic calendar, Saturday is in Red). The Chapter ring is new, in Burgundy to match the dial, with a minute marker track and arabics picked out in white at the 5 minute intervals. It's set at an angle, which adds an effective impression of extra depth to the Dial.

I've fitted new Black & White 'MarineMaster' style hands, a segmented 'Broadsword' Hour hand, a segmented 'Arrowhead' Minute hand, and a white 'Needle' Seconds hand with a luminous circle near the tip. I've used a superior luminous treatment on both the hands and the markers, and they glow beautifully after exposure to light, and it lasts for a good spell, a nice bonus on a redialled watch. 

Case Large dual-finish steel Case, in a Satin-brushed finish to the upper surfaces, and a Highly-polished finish to the sides and back - overall in excellent condition, with minimal signs of use (I've had this professionally polished/rebrushed, and it has come up beautifully - I'm struggling to find any marks, and there are certainly no obvious dings or scratches). The case edges remain sharp and nicely defined.

Bezel Bidirectional steel Bezel, firm resistance, turns smoothly with 60 softly ratcheted 'clicks', in very good condition, with a very smart new Black & Silver 'Submariner' Bezel Insert. 

Caseback The screwdown caseback is in very good condition, again expertly polished - there's a faint trace of a scratch that wouldn't polish all the way out, otherwise only minimal marks. The manufacturer wording on the caseback is clear and well defined, and reads as follows: "Seiko, St Steel, 6309-7290 F1, Water Resistant, 6O2112, JAPAN, A, 'Suwa' symbol" plus the Seiko Wave logo in the centre. Please see the caseback photos (click to enlarge):

Crystal New scratch-resistant mineral glass, secured with a tension ring, perfect condition, clear and bright with no marks.  A few 'clickable' close-ups:

Movement Seiko Japanese produced 6309A 17 Jewel Automatic movement. My watchmaker has fully serviced the movement for me. He reports it is in excellent condition, and appears original to the watch. I've regulated it and it is very accurate. The Serial Number indicates the original manufacturing date as October 1986.  All gaskets have been replaced. 

Strap A brand new aftermarket Seiko Z22 'Accordion' style ridged rubber Diver's strap has been fitted, with a floating keeper, along with a new brushed steel buckle. Will comfortably fit a wrist size of up to 8.5" (220mm+).  I've fitted the strap with superior 'fat' Seiko Spring Bars, which work much better with this style strap, and help prevent wear to the case lug holes.  I've taken a few extra pictures of the strap - click to enlarge:

Running condition Running, and keeping excellent time. As well as the full Service, I've regulated the movement. It's been tested electronically, and 'bench-tested' twice on a winder, over at least 24 hours each time, and is accurate to better than +-18 seconds per day max. (anything under 20 seconds a day is excellent for a vintage automatic). 

Measurements Width without crown - 42mm (46.4mm with Crown), Lug to Lug - 45.3mm, depth 12.8mm. Lug Width 22mm. Weight total 102 grams.

Other - This is a very smart Seiko Diver's Automatic watch, in a large 42mm, which wears quite proudly on the wrist as it's almost 13mm deep. Even though it's on a Seiko 'Accordion' style rubber Diver's strap, it's a hefty 102 grams, and feels very solid and well constructed, with a substantial wrist presence. 

My watchmaker has FULLY SERVICED the 17 Jewel Seiko Japanese Automatic movement, which is working beautifully - the watch has been regulated and keeps accurate time.  The custom 'DX' Diver's Dial with the Dolphin logo, the 'MarineMaster' style hands and the classic 'Submariner' style bezel insert go together really well, and add to the iconic Scuba Diver's appearance. The luminous treatment on the Hands and Markers has been upgraded, and is very effective. 

Though pre-owned, this watch really is in very good condition, with only minimal signs of use, and has clearly been maintained well. Plus I've had the case and caseback expertly refurbished, and it looks terrific, as you can see from the pictures.

  I'll send the winning bidder a PDF File with the full Seiko instruction manual, which will show you how to change the day and date and maintain the watch etc.

Here are a few more photographs, starting with some extra views of the case sides - note the sharp case edges, and the nice definition between the contrasting steel finishes - click to enlarge!

And extra pictures showing the enhanced luminous treatment I've used on the Hands and Markers, after brief exposure to a bright light:

This model is of course no longer available, and certainly didn't look like this originally, but I'm sure it will have cost more than my starting price - I'm starting my auction at just 99p, with NO RESERVE - you could get a top Seiko Automatic Scuba Diver's watch, expertly modified, beautifully refurbished, and professionally serviced and regulated, at a real bargain price!