SEIKO 7548-7000 JAPAN J 150M QUARTZ DIVER (PYH018)

SEIKO 7549-7000 (PYH018) is a true 150m diver's watch with quartz accuracy and dependability whose styling legacy is carried on by the SEIKO 7S26 200m SXK007/9 SCUBA DIVER's.



Released in 1978, a time where quartz movements were state-of-the-art, the 7548 shares many parts with the mechanical 6309 movement which were used in the Turtle. You can exchange parts between these movements. In fact, the 7548 is a 6309 with a quartz module. It’s a highly reliable movement, containing almost no plastic parts, 5 jewels and a trimming screw to adjust the speed. A high end movement in it’s time and until today one of the best quartz movements ever.

misc. In 1980 a SEIKO 6306-7000 JDM is priced at 25,000 Yen the SEIKO 7548-7000 was priced @ 35,000 Yen (40% more), in the same time period an OMEGA SEAMASTER AUTOMATIC DIVER ST 366.0858 " BABY PLOPROF " was priced @ 38,500 Yen in Japan.



The PYF028 (7549-7010) 300m quartz tuna, orange dialled PYQ019 (6458-600A) and black dialled PYQ018 (6458-6000) midsize 150m divers, PTJ011 (2625-0010) and PTJ020 (2625-0170)compact 150m divers.
The right hand side of the photo features the black PYH018 (7548-7000) and pepsi PYH011 (7548-700B) 150m full size quartz divers. There is also the orange SAD017 (H558-500A) arnie model with a clear shot of the original strap design that has the decompression limits table on it.




SEIKO 7548 150M QUARTZ DIVERS
by HYUNYOUB SHIM July 15, 2019

It is well known among vintage dive watch collectors that real US Navy divers wear Seiko dive watches--not the Rolex Submariner, as most vintage watch dealers want you to believe. US Navy divers perform a variety of underwater tasks on ships and submarines that include hull inspection and cleaning, installation and removal of equipment, and welding repairs to enable damaged vessels to continue steaming and complete their missions. While performing these tasks, they usually wear a Seiko either on the supplied rubber strap or, during off-duty hours, on a metal one such as a jubilee bracelet.



Why a Seiko over a Rolex, you may ask? First, it gets the job done underwater. Second, it is super accurate, especially when powered by quartz. Finally, you can break or lose it and not feel guilty about it because the entire package costs less than a Rolex bracelet.



Since the early 80's, Seiko dive watches, especially the 150m quartz model pictured here, have been popular with US Navy divers. Collectors call them "Seiko 150m quartz diver," but more accurately, it is a "Seiko 7548 diver," because it uses a quartz movement labeled with that number.



General Norman Schwarzkopf

SEIKO 7548-700F "SQ" dial
Dark blue dial and pepsi bezel

One of the most famous use cases of a Seiko 7548 diver by someone in the US military, however, was not a diver but an Army General by the name of Norman Schwarzkopf. He described the use of the watch himself:

"I always wore two watches during the [Gulf] war. The one on my left arm was set on Saudi Arabian time and the Seiko on my right arm was set on Eastern Standard Time. That way I could quickly glance at my watches and instantly know the time in both Saudi Arabia and Washington, D.C."

Though some might disagree, his choice for Seiko 7548 diver actually makes it a military field watch.
from Author: Hyunsuk Seung

note: "SQ" stands for SEIKO QUARTZ and were printed on the dials of watches meant for overseas sales [non japanese domestic models]

SPECIFICATIONS:

MOVEMENT: SEIKO Quartz Cal 7548, 5 Jewels, 32’768 Hz
OEM CIRCUIT BLOCK BOARD SEIKO 7548/7549 MOVEMENT FIVE JEWELS

CASE: Stainless steel (diameter: 43 mm excl. crown, lug-width: 22 mm), Screw-in case back, Screw-down crown, Bidirectional rotating elapse-time bezel

OEM CRYSTAL: 320W10GN Hardlex

CROWN Ref.# 70W22NS1

WATER RESISTANCE: 150 m (Pressure-tested)
PRODUCTION PERIOD: 1978 thru1985

OEM battery SEIKO SR43SW
universal replacement part number currently is a #386 battery.

OEM GASKETS:

Ref.# OK0240B0A - CROWN Gasket
Ref.# OC3060B0A - CASE BACK Gasket
Ref.# 0C3660B02 - BEZEL Gasket
Ref.# EC3160B04 - CRYSTAL Gasket

There are the typical black and Pepsi versions, an orange version and even an extremely rare green version.
image borrowed from cyber space

SEIKO Quartz DIVER series

Variants:

7548-7000 Black dial and black bezel - SQ and non-SQ versions
7548-7009 Black dial and black bezel - SQ dial
7548-700A Orange dial and black bezel - SQ dial
7548-700B Dark blue dial and pepsi bezel
7548-700C Orange or (very rare!) Green dial with black lume border and black/gold bezel/hands
7548-700F Dark blue dial and pepsi bezel- SQ dial
7548-700H Orange SQ dial with silver lume border and black bezel - maybe also non-SQ dial



Near end of the production run:

TWO - 200m versions available with screw down crystal retaining ring just like the 7c43-7xxx 200m quartz divers

7548-7010 Black dial and black bezel
7548-701A Orange Dial and black/gold bezel





1983 SEIKO 7548-7000 JAPAN J 150M Quartz Diver

One of my favourite Seiko references.

great bunch !!!

I absolutely love the 7548s! In my Opinion the best vintage diver for daily wear. I have a few of them and this one is my best example: 7548 700b almost nos

I think it's fairly well nailed down by now: the actual watch was auctioned by Antiquorum, the letter of provenance by Schwarzkopf himself mentions a "Seiko 150m quartz diver's watch" (which can only be the 7548), and the catalogue photo shows a US-spec 7548:


In any case, it couldn't have been an SKX009, as the SKX only came to market well after he retired (1996 vs 1991 IIRC).

thanks for sharing additional info, i will insert the image u shared with the information posted for the 7548

I put on a watch protector that was popular in Japan a long time ago.
The purpose of the protector was to protect the bezel and the glass, so the visibility after installation was quite poor.

I saw a lot of people wearing them on divers' watches. Of course, there were people wearing them on the 7548-7000 as well. Old Japanese style😉

New 7548-7000 arrived today.
It is in very good condition.
Battery is dead though☕.

Awesome history and info, thank you. I am always very fond of 7548 and 7C43 quartz divers for their reliability, accuracy and their wonderful history.

Here are my 7548 and 7C43 collection:



You can never go wrong with Seiko, and 7548 - 7C43 are no exceptions.

Serdal.