The Zenith Chronomaster Original and Omega Speedmaster First Omega in Space (FOiS) suit different priorities: Zenith offers a 38 mm case and a high-frequency El Primero 3600 chronograph with a 1/10-second indication; Omega’s 39.7 mm FOiS leans on its Speedmaster identity and a caseback commemorating Walter Schirra’s Sigma 7 mission. Neither is a universal winner. The better choice depends on which design, chronograph character and story matter most to you.
At a glance: the cited references
This comparison uses Zenith reference 03.3200.3600/69.C902 and Omega reference 310.32.40.50.06.001, the leather-strap FOiS identified by Omega Japan. The figures below are manufacturer information, not independent measurements. Zenith’s current product page supplies a fuller specification set; Omega’s official Japan result supplies the FOiS reference, diameter and calibre name, but its underlying product page could not be retrieved, so several fields remain unverified.
| Detail | Zenith Chronomaster Original | Omega Speedmaster FOiS |
|---|---|---|
| Cited reference and configuration | 03.3200.3600/69.C902 [Zenith official product page] | 310.32.40.50.06.001, leather strap [Omega Japan official result] |
| Case diameter | 38 mm (Zenith) | 39.7 mm (Omega Japan) |
| Movement | El Primero 3600, automatic, 36,000 vibrations per hour (5 Hz) (Zenith) | Calibre 3861 is named by Omega; other movement specifications are not verified in the retrieved content. |
| Chronograph information | Zenith advertises a 1/10-second indication. | A directly comparable chronograph specification was not available in the retrieved Omega content. |
| Power reserve and water resistance | Approximately 60 hours and 5 ATM (Zenith). | Not verified in the retrieved Omega content. |
| Heritage emphasis | Design language drawn from the 1969 A386, updated around the El Primero. | Caseback commemorates October 3, 1962 and the Sigma 7 mission, according to Omega. |
What separates their chronographs?
Zenith: a high-frequency movement and tenths display
Zenith specifies an automatic El Primero 3600 running at 36,000 vph, or 5 Hz, and advertises a chronograph indication in tenths of a second. That makes the chronograph display a distinctive part of this reference’s appeal, rather than simply a stopwatch function paired with a heritage design. Zenith lists an approximately 60-hour power reserve and 5 ATM water resistance for the cited watch. Those are manufacturer specifications, not claims about measured performance in daily wear. Zenith’s product page has the reference’s listed details.
Omega: calibre named, comparison details limited
Omega’s Japan result associates the cited FOiS reference with calibre 3861. Because the official product page could not be retrieved, the available material does not establish a complete set of movement or chronograph specifications for this exact configuration. It would be misleading to infer comparative accuracy, reserve or chronograph behavior from the calibre name alone.
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- Stainless steel case
- Black dial
- Swiss-automatic movement
- Case diameter: 40mm
- Water resistant to 330 feet
Two different heritage stories
Zenith and the A386
Zenith dates the A386’s debut to 1969 and describes it as one of the first steel watches equipped with the El Primero. The brand presents the Chronomaster Original as retaining the A386’s design language while updating its performance with a modern El Primero movement. The historical framing comes from Zenith’s June 29, 2021 press release.
Omega and Sigma 7
Omega’s Japan result describes a FOiS caseback bearing “THE FIRST OMEGA IN SPACE” and “OCTOBER 3, 1962” around a seahorse motif, connecting that date with Walter Schirra’s Sigma 7 mission. This supports a specific commemorative link between the watch and the mission; it should not be treated as a complete account of the broader Speedmaster or NASA history. The product information is from Omega Japan’s official result.
Rank #2
- Model 310.32.42.50.01.001
How to choose between them
Choose the Zenith if these are your priorities
- You want the smaller stated case diameter of these two cited references: 38 mm.
- The El Primero 3600, its 5 Hz frequency and the 1/10-second chronograph indication are central to your interest.
- You prefer the Chronomaster Original’s interpretation of the A386 design lineage.
Choose the FOiS if these are your priorities
- You are drawn to the Speedmaster identity and Omega’s specific Sigma 7 commemoration.
- You prefer the stated 39.7 mm case size of the leather-strap reference.
- The caseback’s connection to October 3, 1962, rather than the Zenith’s El Primero display, is the more compelling story for you.
Check the exact watch before deciding
Diameter alone cannot predict wrist fit or perceived bulk. The available specifications do not establish case thickness, lug-to-lug length, or how either model feels on a particular wrist. If possible, try the exact reference and strap or bracelet configuration you intend to buy. Dial preference and legibility are personal as well; inspect the actual configuration rather than assuming every variant looks or wears the same.
For a price comparison, use the same market and a like-for-like configuration. The evidence here does not establish a comparable current Omega price, matched regional prices, warranty terms or service costs. A price for one Zenith variant in one country would not settle which watch offers better value against a different Omega configuration or market.
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Rank #3
- Omega Speedmaster Chronograph Automatic 38 mm Watch 324.30.38.50.03.001
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
