1985 CWC G10 'Medium Fatboy' Royal Navy issue quartz field watch
Excellent/near mint condition
£355.00
Out of stock
The early CWC G10s, from 1980-82 were the real 'Fatboy' G10s, with the deep case to accommodate the ESA/ETA 536.121 movement. From 1987 onwards, CWC G10s were produced with a thin case and low profile case back. In-between, from 1983-85 were a sequence of variants collectively knows as the 'Medium Fatboy' G10s.
The 1985 version is in many ways the archetypal G10 and combines features of both the earlier Fatboys and later thin case versions.
Although the mid-case of the 85 variant is the same as the later thin case watches, the case back is much deeper and includes an anti-magnetic plate inside the case back. This gives the watch a bit of extra heft compared to the later watches. It also retains the earlier 'Swiss' marking at the 6 position, which was replaced with 'Swiss Made' after 1987, and has heavier lines on the minute track that other years of issue.
The movement for the 85 watches is an ETA 555.115, virtually identical to the 955 series movements in the later thin case G10s. This is easy to maintain and parts are mostly compatible with the 955 series movements so it is a practical and maintainable watch to own in the long run. The case back is also far easier to open than the 1980-82 Fatboys, again enhancing its maintainability.
This example is in excellent condition, as described in the condition report, and has just been fully serviced.
The watch is supplied on a new grey and black striped 'James Bond' ribbed NATO strap.
The case and back are very clean and have only minor marks from use - overall they are in excellent condition. The case back has the correct markings including the 0552 Royal Navy service code, NATO stock number, serial number and issue year. The crystal is in good condition and has correct matte tension ring. The dial and hands are in mint condition, with good lume colour. Please refer to the images to make your own judgement about the cosmetic condition of the watch. The images form an important part of the description.
The watch was subject to a full stripdown, clean and service in January 2026. The case parts were stripped and ultrasonically cleaned and the original ETA 555.115 movement was serviced.
The movement was fully stripped, mechanically and ultrasonically cleaned using waterless solutions and hot air dried. The movement was rebuilt and lubricated using Moebius oils. Images of the movement rebuild are included in the listing. The watch hacks and sets from the crown correctly. All the seals were also replaced and greased, including the back gasket, the battery hatch and crown gaskets.
The watch was regulated on a quartztester machine and is running on the bench at -0.01 seconds per day, or -0.3 seconds per month, which is well within the +/-10 seconds per day specification. Note that accuracy may differ from this when in use.
The watch is absolutely suitable for everyday use, but it is vintage watch so is not recommended for sports or use in extreme conditions. The watch has not been pressure tested so water resistance is not guaranteed. This watch is covered by our waterproof 6 month guarantee.
Issued: Yes
Issue details: UK MoD
Date of manufacture: 1985
Production numbers: c15600
Movement: ETA 555.115
Diameter: 36mm
Lug width: 18mm
Hacking: Yes
Case back: Snap
Screwdown crown: No
Bracelet: NATO
UK MoD issue
1985 'Medium Fatboy'
Original ESA 555.115 quartz movement
Recently serviced and regulated
Excellent condition
Supplied on new ribbed NATO-type strap
6 months non-waterproof guarantee
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