Sinn 903
 

Sinn 903 vs Navitimer: Why It’s More Than an Homage

6 min read
Safie Agar-Hutton

Brands

Sinn

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Brand Focus

Safie Agar-Hutton

Brands

Sinn

Categories

Brand Focus

Is the Sinn 903 actually a Navitimer? I hear you cry.


Well—sort of. The full story involves a bit of a history lesson, tracing back to the original Breitling Navitimer and the dramatic twists the brand faced in the 1970s.

Breitling Navitimer History

1966 Breitling Cosmonaute Navitimer
1966 Breitling Cosmonaute Navitimer on Genuine Vintage Bond Military Nylon Watch Strap. Credit - WatchGecko

Back in 1952, Breitling introduced the legendary Navitimer, cementing its reputation as a brand synonymous with aviation. Not long after, the Navitimer was crafted specifically for the Aircraft Owners and Pilots Association (AOPA), helping it become one of Breitling’s most iconic models ever.


For a while, the Navitimer was basically Breitling’s golden goose. But those good times didn’t last forever. The 1970s brought the quartz crisis, hitting the Swiss watch industry hard — and Breitling was no exception. Staff layoffs followed, mechanical watch sales plummeted, and by 1979, parts of the company were liquidated, with Breitling’s doors closing temporarily.

How Sinn Took Over the Navitimer Legacy

Sinn 903
Sinn 903. Credit - WatchGecko

After Breitling’s decline, the rights to the Navitimer were split between Sicura and Sinn. Sinn acquired the rights to the iconic Breitling 806 and 809 models, along with 500 cases and dials, eager to craft a pilot’s watch featuring the signature logarithmic scale and slide rule that made the Navitimer so legendary.


Meanwhile, Sicura continued producing watches under the Breitling name, holding the rights to both Breitling and Navitimer brands. Sinn, however, focused on advancing the Navitimer design with innovative technology—efforts that gained serious momentum when Lothar Schmidt took the helm in 1993.

Founded in 1961, Sinn built a strong reputation for engineering some of the finest tool watches in the business. Their innovations range from Ar-Dehumidifying technology and antimagnetic cases to Tegiment steel hardening and temperature-stabilized movements. Sinn’s rugged timepieces became trusted gear for German police, firefighters, astronauts, and pilots—thanks in part to their lineup of TESTAF-certified pilot watches.

The Sinn 903 ST B E: What You Need to Know

Sinn 903
Sinn 903. Credit - WatchGecko

Now, let’s talk about the Sinn 903 itself—specifically the 903 ST B E Navigational Chronograph. Since acquiring the rights to the original 806 and 809 Navitimers, Sinn has steadily refined this series, culminating in the modern 903 ST we know today. It’s an impressive piece, housed in a 41mm stainless steel case that proudly showcases the famous slide rule and logarithmic scale, packed with functions made possible by Sinn’s decades of technical innovation.


The case features a mix of polished and satin finishes, standing 14.5mm tall to accommodate the slide rule scale beneath a domed sapphire crystal with anti-reflective coating. The bezel’s grooved texture suggests it might be unidirectional, but all slide rule calculations and the internal rotating scale are actually controlled by the smoothly turning crown at 10 o’clock—a detail I discovered after poring over the detailed manual, which dedicates a whole section to mastering the slide rule functions.

Sinn 903
Sinn 903. Credit - Sinn

But the real star is the dial. With an intricate, tool-watch aesthetic, the 903 packs the slide rule with logarithmic scale alongside three subdials designed for everything from mathematical conversions to calculating fuel consumption, speed, and distance. The chronograph function also lets you track elapsed time with precision.


Visually, the dial is a treat: a deep blue electroplated face with silver markers and counters that shimmer with a faint velvety texture. The ivory luminous coating on the hands and raised indices ensures excellent legibility and complements the blue beautifully. A date window sits discreetly at 4:30, colour-matched so it doesn’t interrupt the dial’s flow, while the seconds hand pops in white and red for quick, easy reading during calculations.


Flip the watch over, and the LJP 8000 self-winding movement is on full display through a sapphire caseback. It runs at 28,800 semi-oscillations per hour and includes a seconds stop function. The 903 ST B E also boasts anti-magnetic protection (DIN 8309) and is waterproof and low-pressure resistant to 100 metres (DIN 8310), making it as tough as it is functional.

So, It Isn’t Just a Navitimer Homage?

To put it simply, the Sinn 903 ticks all the Navitimer boxes—and it does so at about half the price of a Breitling. It never feels like a mere knock-off; instead, Sinn has clearly respected the design elements that made the Navitimer iconic, while expanding and refining them to suit today’s watch enthusiasts.


The biggest hesitation some might have is the desire for “the original Breitling Navitimer.” But unless you’re lucky with an eBay find, those originals are hard to come by—and every Navitimer made after 1979 was actually rebranded by Sicura. In many ways, the Sinn 903 feels like a purer continuation of the original Navitimer spirit than the modern watches sold under the Breitling name.


And since the 903 deserves a strap that matches its heritage and style, let’s explore some of the best WatchGecko straps that complement this remarkable pilot’s watch perfectly.

Beaufort Racing Badalassi Carlo Minerva Box Leather Perforated Watch Strap

For a strap that channels the 903’s vintage aviation charm while adding a dash of sporty character, the Beaufort Racing Perforated Strap in Badalassi Carlo Minerva Box leather is a natural fit. The soft, high-grade Italian leather feels superb on the wrist, while the classic rally-style perforations nod to both motorsport and cockpit heritage. On the Sinn 903, it brings out the chronograph’s utilitarian roots without overwhelming its intricate dial—perfect for everyday wear with just the right amount of retro flair.

Original Vintage Highley Genuine Leather Watch Strap

Sinn 903 on Original Vintage Highley Genuine Leather Watch Strap

For a timeless leather pairing, the Original Vintage Highley Genuine Leather Strap is hard to beat. Its thick, gently padded profile and lightly distressed finish complement the Sinn 903’s tool-watch credentials while softening its technical aesthetic just enough for everyday versatility. Available in a range of rich, earthy tones, the strap gives you the freedom to tailor the look—whether you want to contrast the black dial, bring warmth to the case, or lean into vintage vibes. It’s a classic match for a chronograph with serious heritage.

Vintage Style Perforated Rubber Watch Strap

Sinn 903 on Vintage Style Perforated Rubber Watch Strap
Sinn 903 on Vintage Style Perforated Rubber Watch Strap. Credit - WatchGecko

If you’re after something a little sportier and more practical, the Vintage Style Perforated Rubber Strap is a standout option for the Sinn 903. The vintage rally-inspired design ties in effortlessly with the chronograph’s aviation-meets-motorsport aesthetic, while the soft, supple rubber adds lightweight comfort and daily wearability. We’ve paired it with green for a subtle military edge that plays well against the black dial, but with a wide range of colours available, it’s easy to customise the look to suit your style—whether you’re going bold or keeping it classic.

Genuine Vintage Bond Military Nylon Watch Strap

Sinn 903 on Genuine Vintage Bond Military Nylon Watch Strap
Sinn 903 on Genuine Vintage Bond Military Nylon Watch Strap. Credit - WatchGecko

For a pairing that speaks directly to the Sinn 903’s aviation and military roots, the Genuine Vintage Bond Military Nylon Strap is a natural fit. Inspired by classic British MOD-issued straps, it offers lightweight durability, quick-drying performance, and a secure fit that makes it ideal for daily wear or field use. The iconic striped design adds just the right amount of rugged flair without competing with the complexity of the dial. It’s a practical, heritage-rich option that feels right at home on a tool watch with such storied lineage.

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Safie Agar-Hutton

About the Author: Safie Agar-Hutton

Safie is the Editor of WatchGecko Magazine and a lifelong storyteller with a deep fascination for timepieces discovered in her twenties. She engages readers with insightful news, release updates, and captivating stories from the world of horology, bringing the rich narratives of watchmaking and design to life for the magazine’s audience.

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