EVERYTHING YOU NEED TO KNOW ABOUT THE ZENITH EL PRIMERO

In the 1960s, the race to develop the first automatic chronograph was highly competitive. Several watchmakers, including Zenith, Heuer, Breitling, and Seiko, were vying for this technological breakthrough. Zenith's project, codenamed "3019 PHC," aimed to create not only an automatic chronograph but one with unmatched precision. On January 10, 1969, Zenith officially unveiled the El Primero, meaning "The First" in Spanish. What set it apart was its high-frequency movement, beating at 36,000 vibrations per hour (vph), allowing it to measure time with an accuracy of 1/10th of a second. 

It also featured an integrated column-wheel mechanism and a power reserve of 50 hours—remarkable technical feats at the time. This was one of the world's first automatic chronograph movements, this is why the watch gained huge popularity with motorsports as other than Heuer at the time, very few watch brands could make accurate chronographs. With the El Primero movement becoming something of a legend, it was later used in watches by other renowned brands, including Rolex for its Daytona chronograph.

One of their most famous models, the G381, was among the first models to be crafted out of gold designed to house the El Primero calibre after its launch in 1969 and is considered the gold counterpart of the iconic A386, another El Primero classic. It still had the same round case, decimal and tachymeter scales. It was produced in multiple small batches from 1969 to 1972 but Zenith only ever produced around 1000 pieces. 

What would later go on to become the base-design for ZENITH’s signature Chronomaster Sport line, the A386 was launched in 1969 in a more classical round-case with straight lugs chronograph watch. The classic stand-out features remained their famous tri-colour chronograph counters and the decimal scale, becoming one of the most significant references in the history of the El Primero calibre and an icon among chronograph wristwatches.

Like many Swiss watchmakers, Zenith faced difficulties during the Quartz Crisis of the 1970s and 1980s, when inexpensive quartz watches from Japan disrupted the traditional mechanical watch industry. During this period, Zenith's mechanical watch production was nearly discontinued and they were massively struggling to turn a profit from their historic pieces. However, Charles Vermot, a dedicated watchmaker at Zenith, secretly preserved the blueprints and tools for the El Primero movement, ensuring its survival. In the 1980s, mechanical watches regained popularity thanks to Gerald Genta and his famous steel-sports watches with integrated bracelets, and Zenith made a strong comeback. The company was acquired by the luxury group LVMH in 1999, which provided the resources to revive and expand the brand.

In the 1980s, as interest in mechanical watches rekindled, brands sought high-quality automatic chronographs. Rolex, looking for a reliable movement for its Daytona model, turned to Zenith’s El Primero. The collaboration lasted until 2000 and played a significant role in reaffirming Zenith’s status as a premier watchmaker. Zenith itself reintroduced the El Primero in various models, further refining the movement while maintaining its core characteristics. The brand also developed new versions, such as the El Primero 400, enhancing reliability and efficiency.

Today, the El Primero remains a cornerstone of Zenith’s collections. Modern iterations, such as the Defy El Primero 21, have pushed technological boundaries further, featuring a movement capable of measuring time to 1/100th of a second. With over five decades of excellence, the El Primero continues to be celebrated by collectors and watch enthusiasts worldwide. Its influence extends beyond Zenith, shaping the evolution of high-frequency chronographs across the industry. On their website there is even a section called ‘Icons’ where you can buy any of their old historic model as and when they have them in stock. 

In 2025 zenith has a plethora of El Primero watches that have been modernised and transformed into your classic luxury Chronograph watch. As such, Zenith have renamed the line to the Chronomaster Sport all of them drawing heavy inspiration from their classic El Primero models. This of course is no bad thing, it’s a rare skill for watchmakers to be able to create something new that draws on designs features from their classics without directly copying them. 

And that’s exactly what the Chronomaster Sport is, a modern day El Primero that gives you a similar package to the Rolex Daytona but from the original chronograph watchmaker themselves. With well over 40 different models to choose from it’s safe to say that Zenith has not held back on creating various different designs to enable everyone to get their perfect chronograph watch.

At the heart of the Chronomaster Sport is the latest generation of the El Primero movement, the impressive and famous caliber 3600. This high-frequency movement operates at 36,000 vibrations per hour (5 Hz), allowing it to measure and display elapsed time with a precision of 1/10th of a second, just like its original sibling the El Primero. It offers a power reserve of approximately 60 hours which for a chronograph is very impressive as they require more energy with the extra functions using up precious power.

Zenith over the years has expanded the Chronomaster Sport line with several notable variations. One of their first models that grabbed a lot of attention from watch enthusiasts was the Chronomaster Sport Open which was first introduced in 2022, this model features a partially open dial, revealing the beating heart of the El Primero movement. It comes in a more modest 40mm case and offers dial options in black or silver. 

The great thing about the Zenith Chronomaster Sport watch is that because it has a few different colours incorporated into its design, you can really have some fun when it comes to rubber strap colours. With it being a classic chronograph with a slightly different spin, it is still a proper tool watch and as such it can be worn during any sporting activities too. 

However, you might not want to risk scratching your original bracelet or you might want a comfier and sportier feel/look to your watch. ZEALANDE specialise in designing and creating the best rubber straps for your Zenith watches and with there being 10 different colours to choose from, you can really have some fun with this watch. You could easily put on a classic white or black strap for a cleaner look but equally, it would look fantastic with a red or orange colour to match and complement the dial colours.