What's on your wrist

Watches Past and Present

Seiko 7K52 Scuba master

Posted by Derek on October 30, 2012 at 1:25 PM

 

I am a big fan of Seiko’s and though many pieces they produce leave me cold a lot of them are beautifully engineered and every now and then they hit the spot. Certainly some of their vintage watches are cracking pieces of watch history, and they did come up with innovative design features.

 

But sometimes I wonder what goes through the head of a Seiko watch designer. For example the watch this thread is about, the Seiko 7K52-6A19 (SLD005) is a complex analogue watch. I am sure in the late 90’s (when it was made) there were perfectly capable dive computers which could tell you the depth and time of dives. But someone at Seiko decided to create an analogue version. Seiko are good at innovation but sometimes at the expense of common sense, as NeilC once said about Spring Drive “why invent something that didn’t need inventing”, but that’s what I find intriguing about Seiko they don’t let common sense stand in the way of innovation.

 

The 7K52 is claimed to be “world’s first fully automatic analogue depth sensor”, the 7K52 movement has a pressure sensor on the case side, and this will feed details to the hands once in water automatically. It has 9 hands, “how do you tell the time” I here you say, it can be difficult to read the time but wearing it for a while it becomes quite easy, and I found another design feature which helps with identifying the hour, minute and second hands, which I will talk about later.

 

The watch is designed for recreational diving (non-decompression), so what can this watch do

Time/Calendar/Alarm and importantly

Diving Measurement

• Full automatic measurement of diving data

Current depth, maximum depth, diving time and time submerged

• Recording of log data

Maximum depth, average depth, diving time and time submerged for the last two dives

• Warning functions

• Rapid ascent warning

• Extra measurement range warning

• Abnormal measurement warning

• Rotating bezel

Can measure elapsed time such as diving time, surface interval, etc.

• Battery life indicator

Here is a page from the instruction booklet detailing the hand layout

 

Here is a page from the instruction booklet detailing hand function

 

Some Facts:

How does it measure up:

Diameter: 46mm without the crown and 50.6mm with.

Lug to Lug: 52mm

Thickness: 15.5mm

Lug width: 22mm

Crown is screw down

 

What is it made of:

Case and bracelet are Stainless Steel

Crystal is sapphire

The water resistant rating is 200m

The bracelet is solid with flip lock clasp with dive extension.

Technically I suppose this Seiko is not a Scuba Master as it doesn’t have this written on the dial or caseback unlike its cousin the 7K52-6A00. Attractive as it is, particularly with the gold bezel, I couldn’t get past the titanium.

7K52-6A00

 

The lume on the watch is the usual Seiko fantastic, this watch is 14 years old but glows as soon as it suspects a shadow is approaching. The lume markers at 12, 3, 6 and 9 are a different shape to the others, with the 12 marker different to the 3, 6, and 9 making orientation easy.

 

I mentioned earlier how having all these hands can make reading the hour and minute hand difficult. I noticed that if the watch is angled in any light the reflection off the steel hour, minute and second hands make them stand out, making them very legible, whether this was a deliberate design feature I don’t know, but I would like to believe this was considered in the design.


Summary

These were made in mid to late 90’s, mine’s a 1998 vintage despite its beastly size it is all in proportion which makes it very wearable, if your wrist size is 7inch or above. The dial has great depth; it needs to be so it can accommodate all the hands. The box it comes with clearly shows this watch means business with depth log, compass and temperature gauge. A spare rubber strap, strap changing tool and compartment for the instructions.

(pic taken from a previous 7k52)





This is my third 7K52 over the years and hope to hang on to this for a while. There are other interesting models with a 7K movement.

ScubaMaster 7K52-6A00 (as above but Titanium) 



Cruising Master 7K36-6A00

Marine Master 7K32-0A20


Land Master 7K32-0A10


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2 Comments

Reply [email protected]
5:18 AM on December 17, 2013 
Hi. Do you know where I can find parts for 7k52 6A00
Reply Derek
5:19 PM on December 19, 2013 
[email protected] says...
Hi. Do you know where I can find parts for 7k52 6A00


You can try contacting Seiko direct, or keep an eye out on eBay.