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Zenith Defy Extreme Diver 42.5mm Mens Watch Blue Interchangeable Strap
Ref. 95.9601.3620/51.I301
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Stepping up in Zenith's range
Defy Skyline Chronograph 42mm Mens Watch Blue Interchangeable Strap£12,500
Defy Skyline Chronograph Skeleton 42mm Mens Watch Blue Interchangeable Strap£14,500
Defy El Primero 21£12,400
Defy Skyline Chronograph 42mm Mens Watch Silver Interchangeable Strap£12,500
Defy Skyline Chronograph 42mm Mens Watch Black Interchangeable Strap£12,500
The angular 42.5mm titanium case gives the Defy Extreme Diver a distinctly geometric profile, kept lightweight by the metal's properties. A rotating blue ceramic bezel and helium escape valve underpin the 600-metre water resistance rating. The blue dial features a star-patterned texture with luminous markers and hands for low-light legibility. Inside runs the El Primero 3620 SC automatic movement, offering a 60-hour power reserve displayed on the dial. The watch ships with interchangeable straps — blue rubber, titanium bracelet, and a single-piece fabric strap made from recycled fishing nets — each swapping without tools.
- Reference
- 95.9601.3620/51.I301
- Brand
- Zenith
- Collection
- Defy
- Case size
- 42.5mm
- Case thickness
- 15.5mm
- Case material
- Titanium
- Case shape
- Round
- Dial
- Blue
- Crystal
- Sapphire
- Bezel
- Unidirectional rotating
- Movement
- Automatic
- Calibre
- 3620 SC
- Functions
- Date
- Water resistance
- 600m
- Bracelet / strap
- Titanium bracelet
- Strap colour
- Blue
- Lume
- Super-LumiNova
- Retailer
- Goldsmiths
Additional specifications
- Power reserve
- 60 hours
- Strap
- Interchangeable
Learn more about Zenith
Georges Favre-Jacot founded Zenith in Le Locle in 1865, aged twenty-two, with an idea that was radical for the Swiss industry: bring every trade needed to make a watch — movement, case, dial, hands — under one roof and one management. The integrated manufacture was largely his invention, and the Le Locle site he built is still in use.
The approach produced results at observatory trials, where Zenith accumulated more precision awards than any other manufacture. The name itself came from a calibre Favre-Jacot considered the summit of his work.
Its defining achievement is the El Primero of 1969, developed over seven years and announced in the same year as the Heuer-Breitling consortium's Calibre 11 and Seiko's 6139. It was an integrated automatic chronograph beating at 36,000 vibrations per hour, allowing measurement to a tenth of a second — a frequency almost nothing else matched for decades.
It nearly did not survive. When American owners ordered the mechanical tooling scrapped during the quartz crisis, a watchmaker named Charles Vermot hid the plans, presses, and cams in a walled-off attic. When demand for mechanical chronographs returned, Zenith could restart production because of him. Rolex used the El Primero in the Daytona from 1988 to 2000.
LVMH acquired Zenith in 1999.
- 1865
- Georges Favre-Jacot founds the integrated manufacture at Le Locle.
- 1969
- The El Primero automatic chronograph debuts at 36,000 vph.
- 1975
- Charles Vermot hides the El Primero tooling from destruction.
- 1988
- Rolex adopts the El Primero for the Daytona.
- 1999
- Acquired by LVMH.
Also in 1 collection
This watch appears in the Zenith Defy range (23).
Best of 2 retailers
What the specifications mean
A mechanical watch built to be worn hard and got wet.
Strengths
- 600m water resistance, rated for actual diving
- Sapphire crystal, which resists scratching
- Luminous hands and markers for low light
- Sits in the lower half of Zenith's range as we list it
Worth knowing
- 15.5mm thick, so it will not disappear under a cuff
Your new watch
Frequently asked questions, and things you should know about this watch
Can I swim with it?
Yes. At 600m it is rated for swimming, snorkelling and recreational diving.
Water resistance explainedWill the glass scratch?
Unlikely. Sapphire is second only to diamond in hardness and shrugs off everyday marking.
Sapphire, mineral and acrylic comparedDoes it need a battery?
No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.
Quartz, automatic and solar comparedHow long does it run for when it's not worn?
About 60 hours fully wound — enough to survive a night off the wrist, but not a full weekend.
Is it a men's or women's watch?
Listed as men's.
Cheapest place to buy
Both Mappin & Webb and Goldsmiths list it at £10,600, so choose on delivery and warranty rather than price.
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