LONGITUDE REBORN
In 2015, Zero West introduced its first timepiece, the L1 Longitude – a modern nod to John Harrison’s H4 clock and the Prime Meridian, also known as Zero Degrees West.
Limited to 20 pieces, it soon earned grail status and set our course through time. Ten years on, the new L4 evolves that story, contemporary, composed, and limited to 50 pieces.
TIME TRAVEL
In 1707, the Scilly disaster exposed the deadly cost of sailing without longitude, prompting Parliament’s 1714 Longitude Act. John Harrison’s H4 answered the challenge—seconds-accurate over an 81-day sea trial—and navigation changed forever. In 1884, Greenwich became zero degrees, the prime meridian, the line that starts every map and day. The L4 Longitude honours that lineage: British ingenuity, hard-won accuracy, and a clear line back to zero.
THE MERIDIAN REVEAL
Every L4 Longitude displays the world on its back. Our in-house R&D team reverse-prints the sapphire with a deep-navy globe and meridian lines, placing the Prime Meridian at your centre – a refined salute to British horology and the spirit of the L4.
CLARITY THROUGH DESIGN
Good design is obvious, great design is transparent and the L4 is a master of this mechanical discipline. Displaying high-contrast indexing, crisp typography, and an optically correct sapphire crystal to prioritise legibility in all conditions. Regulated in-house to our Chrono10 standard, the L4 keeps its focus where it matters: accurate time keeping at a glance.
TECH SPEC
Each model in the collection continues to reflect Zero West’s commitment to precision engineering, innovative DualConcentricConstruction™, and distinctive design elements.
- Latitude and Longitude reference Greenwich and the main line of longitude
- Date code references when London was awarded the Prime Meridian, ‘Where time starts’
- White dial, roman numerals and blue hands are a contemporary nod to John Harrisons H4
- Five-axis, aerospace grade 316L stainless steel machining
- Hand-assembled, regulated, and tested in-house
- 42mm diameter, 316L Stainless Steel, matt body finish with polished lugs
- Zero West DualConcentricConstruction™ (DCC™)
- Polished stainless steel back with inset reverse printed sapphire crystal
- Water resistance: 10ATM (100m)
- Main Crown – Matt silver finished sprung, screw-down with triple seal technology
- Front: Deep‑dome, optically corrected sapphire with AR coating
- Rear: Reverse printed globe graphic from the ‘Z Branch’ workshop
- Sellita Top Premium SW500BVc (automatic chronograph)
- In house regulated
- 28,800vph
- 35 jewels
- Self-winding ball bearing rotor
- Power reserve ~62 hours
- Antique white with 2 recessed chronograph subdials and inset polished rings. Outer tachymeter with inner polished ring
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Overprinted roman numerals set within train track minute markers; Blue teardrop hour and minute hand with polished main sweep. Matching chrome seconds hands
- Recessed subdials at 6 and 12 o’clock
- 42mm diameter
- 15.2mm thick
- 22mm lug width
- 47mm lug to lug pin spacing
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Standard rubber 22/20mm. Zero West custom military and aerospace grade cross-linked fluoroelastomer rubber. Matt silver pin buckle
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Integrated rubber 22/20mm. Zero West custom military and aerospace grade cross-linked fluoroelastomer rubber. Zero West in-house designed deployment buckle
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Leather padded strap 22/20mm. Handmade with the finest Italian leather and hypoallergenic lined. Matt silver pin buckle. Sizes: Long: 195-235mm / Standard 180-220mm / Short: 170-205mm
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Padded leather strap 22/20mm. Handmade with the finest Italian leather and hypoallergenic lined. Zero West brushed silver butterfly clasp. Available in standard size 175mm-220mm
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Metal bracelet 22/20mm. 316 stainless steel, matt silver with polished centre links, designed in-house and uniquely engineered to complement our watch head. Deployment buckle
ZERO WEST – CHRONO10 CERTIFICATION
Chrono10 is Zero West Watches’ proprietary precision testing and certification process, ensuring every L4 timepiece meets the highest standards of accuracy and reliability. Unlike most brands that rely on third-party testing, we perform rigorous in-house evaluations that include multi-temperature testing (8°C, 23°C, and 38°C), six-axis accuracy assessments, and extended stabilization periods before final regulation.
Every Chrono10-certified timepiece leaving our workshop is rigorously tested and regulated to a strict maximum accuracy threshold of −4/+6 seconds per day, with an Average Daily Rate (ADR) target maintained within those limits.
This level of performance is enabled by our commercial partnership with Sellita, who supply us only their Top Grade movements; their statistically controlled batch manufacture and premium materials — including Glucydur balance wheels, Nivachron hairsprings, and quality jewelled anti-shock mounted bearing interfaces — ensure consistent results across our specified real-world temperature range.