Cestrian Ocean Series GMT CO-YLS001 — WatchNation
Cestrian — Ocean Series — Automatic Travel Diver
CO-YLS001 GMT
NH34 Automatic Engine  ·  200m Water Resistance  ·  High-Visibility Yellow Dial  ·  Sapphire Crystal
WatchNation
Authorised Cestrian Retailer
Chester  ·  Est. 10 Years
★ Seiko NH34 Automatic GMT 200m Dive-Rated Capability Authorised Cestrian Dealer 2-Year Official Warranty Distinctive Yellow Textured Dial High-Performance Lume Scratch-Resistant Sapphire Brushed Stainless Steel Bracelet Free UK Shipping 30-Day Returns
Ocean Series Horizon — Bold Contrast Aesthetics & Purposeful Dual-Time Utility

The CO-YLS001 introduces a striking, high-visibility yellow dial option to Cestrian's dependable sports layout. Engineered to transition seamlessly from aquatic environments to global travel, it pairs uncompromising diver strength with an independent 24-hour architecture.

200m
Water Resistance
Our Commitment
Why Buy from WatchNation?
01
Authorised Cestrian Store Network

Every piece in our collection is 100% authentic and obtained directly from the brand networkYour purchase guarantees genuine internal parts and pristine factory conditions.

02
Official 2-Year Manufacturer Warranty

This premium travel-diver model is covered by an official 2-year manufacturer warranty frameworkinsuring internal mechanical tracking and assembly structures against failures.

03
Pristine Original Packaging Assured

We strictly avoid unverified grey-market operations. Your watch will be delivered complete with its original Cestrian presentation box, instruction guide pamphlets, and serial tags.

04
Dedicated High-Street Support

Our experienced customer care experts possess direct product trainingmeaning we can help guide you smoothly through sizing parameters or mechanical operation instructions.

05
Free Tracked Shipping & Flexible Returns

We provide complimentary tracked shipping across the UK alongside a customer-focused 30-day return window to make your buying journey smooth and reliable.

Waterproofing Specifications — Boasting a true 200-metre (20 Bar) depth structural rating anchored by a secure screw-down crown. This mechanical watch is completely qualified for surface swimming, demanding marine sports, and recreational dive tasks.
What Sets It Apart
Key Features
NH34 Automatic GMT CoreProven Mechanical Dual-Time Tracker
Powered by the legendary Seiko NH34 automatic GMT movement, celebrated for its robust durability and straightforward servicing. This self-winding mechanical engine accurately drives an independent fourth hand to monitor a secondary time zone cleanly over a 24-hour cycle.
High-Visibility Yellow DialTextured Depth & Bold Character
Features a distinctive, eye-catching yellow watch face with a textured finish that captures light dynamically. This vibrant backdrop is purpose-engineered to maximize visibility, injecting an energetic and adventurous personality into the Ocean Series line.
High-Performance LumeExcellent Day & Night Orientation
The applied hour markers and hands are generously equipped with a high-performance luminescent compound. This choice ensures strong, reliable legibility across changing environments, from direct midday sun to pitch-black underwater conditions.
Scratch-Defiant Sapphire LensUncompromising Display Shielding
The watch face is fully armored beneath a hardened scratch-resistant sapphire crystal lens. Chosen for its extreme material density, it guards against surface abrasions to maintain unhindered legibility through years of hard use.
Contrasting GMT Tracker HandBalanced Visual Segmentation
Outfitted with a high-contrast GMT pointer hand that effortlessly details second-timezone readouts. This sharp visual segregation allows for instantaneous tracking without overwhelming the dial’s highly clear, instrument-focused layout.
Micro-Adjust Bracelet LinkFully Brushed Stainless Steel
The solid steel links feature a professional brushed finish to minimize reflection and hide daily scuffs. Complete with a secure deployment clasp and an integrated micro-adjustment system, it allows you to fine-tune the fit instantly for all-day comfort.
CESTRlANOcean

Honest Watchmaking Integrity — Designed for Real-World Environments

Cestrian focuses on engineering purposeful timepieces designed for real-world reliability. By pairing a dive-ready 200m steel case with an automatic GMT travel function, the CO-YLS001 perfectly balances utility and performance. Built with durability, legibility, and honest value in mind, it is a versatile travel partner engineered to go anywhere without compromise.

Comprehensive 2-Year Manufacturer Guarantee Policy

This travel-diver timepiece is fully backed by an official 2-year Cestrian global manufacturer warranty framework. When purchased through our authorized WatchNation store, your registration details are securely logged within our service database, ensuring direct, hassle-free access to factory components and expert watchmaking support.

Technical Details
Specifications
Identity
Brand
Cestrian
Collection
Ocean Series GMT
Model Reference
CO-YLS001
Watch Purpose
Everyday Performance Sports — Tactical Travel Diver Utility
Mechanical Core & Functions
Movement Type
Automatic Mechanical (Self-Winding)
Movement Calibre
Premium Seiko NH34 GMT Engine
Complications
Independent 4th Hand Dual Time Zone Tracking
Service Profile
High-reliability configuration with straightforward servicing
Case & Dial
Case Composition
Solid Marine-Grade Stainless Steel
Crown Engineering
Secure Screw-Down Threaded Crown
Dial Treatment
Bold Yellow Face with Distinctive Light-Catching Textured Finish
Indices & Markers
Applied Index Plots with High-Performance Lume Layout
Crystal Protection
Scratch-Resistant Sapphire Crystal Shield
Bracelet & Depth
Bracelet Type
Fully Brushed Stainless Steel Multi-Link Band
Clasp Structure
Secure Deployment Clasp featuring micro-adjustment slots
Luminescent Fill
High-Performance Luminescent Paint Layer
Water Safety Rating
200M / 20 Bar (20 ATM) — Approved for Surface Water Sports & Diving
Warranty Coverage
2-Year Official Manufacturer Warranty
In the Box
What's Included
Cestrian Ocean Series GMT CO-YLS001 Watch
Original Cestrian Brand Presentation Packaging
Official 2-Year Manufacturer Warranty Booklet
User Instructional Booklet
In Detail
About This Watch

The Cestrian Ocean Series GMT CO-YLS001 stands as a clear expression of the brand's core design values: engineering robust, purpose-driven watches that excel in demanding, real-world environments. This highly capable model expands on traditional dive watch capabilities by integrating the added utility of a dual-time complication. Built as a versatile everyday sports watch, it balances rugged durability with high-contrast legibility in a format that feels natural whether navigating deep waters, handling business travel, or anchoring a casual weekend look.

The mechanical core of this timepiece is the reliable Seiko NH34 automatic GMT movement, chosen by Cestrian for its proven track record, shock resistance, and straightforward long-term servicing. This self-winding calibre drives an independent fourth hand that tracks a second time zone against a 24-hour cycle, allowing global travelers to monitor home time at a glance. The internal movement is protected by a solid, marine-grade stainless steel case that features a threaded, screw-down crown and a scratch-resistant sapphire crystal shield, ensuring an uncompromised 200-metre water resistance rating.

Visually, the watch makes a confident, tactical statement with its vibrant yellow watch dial, intentionally executed to maximize readability while bringing a bold, purposeful character to the Ocean Series lineup. The dial features a detailed textured finish that plays subtly with shifting light conditions, granting extra visual depth. Set against this high-contrast backdrop are applied indexes and a clean hand architecture heavily laden with high-performance lume, securing quick orientation in low-light environments. A contrasting GMT pointer hand indicates your secondary time zone with clinical clarity, delivering essential travel data without cluttering the clean, instrument-focused aesthetic.

Completing the watch is a solid stainless steel link bracelet, featuring a fully brushed finish that resists surface scuffs and glare. The bracelet is fitted with a secure deployment clasp and an integrated micro-adjustment mechanism, allowing you to fine-tune the fit on your wrist as temperature and conditions shift throughout the day. Built with a focus on longevity, functionality, and honest value, the CO-YLS001 is a versatile travel partner backed by an official two-year manufacturer warranty.