Watch reference library
Zenith Chronomaster Sport 03.3100.3600/21.M3100
Specifications
- Case size
- 41mm, 13.6mm thick, about 46.2mm lug to lug
- Case material
- Stainless steel, brushed and polished
- Bezel
- Black polished ceramic with an engraved 1/10th of a second scale
- Dial
- Black matte, with snailed counters in three colors and rhodium-plated faceted hour markers and hands coated with Super-LumiNova
- Movement
- Zenith El Primero calibre 3600, automatic chronograph, 36,000 vibrations an hour
- Power reserve
- About 60 hours
- Water resistance
- 100 meters
- Crystal
- Domed sapphire with anti-reflective coating on both sides, and a sapphire caseback
- Bracelet
- Three-link steel bracelet, brushed and polished, with a double folding clasp and safety mechanism. A rubber strap with a Cordura fabric effect was offered as an alternative
The story
Monochrome Watches traces the Chronomaster to the 1994 Basel fair and calls the El Primero, introduced in 1969, the only one of that year's three automatic chronograph movements still in production. Zenith re-industrialized the movement in 1987 as the calibre 400.
In January 2021 Zenith introduced the Chronomaster Sport, built around the El Primero calibre 3600. The new movement takes advantage of the El Primero's 5Hz beat to display a tenth of a second, with the central chronograph hand making one lap every 10 seconds. A version of the 3600 first appeared in the Chronomaster 2 El Primero Striking Tenth limited editions of 2019, the El Primero's 50th anniversary, according to aBlogtoWatch, and the Chronomaster Sport made it a standard production movement.
The watch also introduced a black ceramic bezel with a 1/10th of a second scale, which Zenith says is the first time that display has been etched onto a ceramic bezel. The 41mm steel case sits between the 38mm and 42mm sizes of the Chronomaster line at the time. The reference 03.3100.3600/21.M3100 is the black dial on the steel bracelet.
What to check before you buy
The reference code carries the details. Monochrome Watches lists four launch references: 03.3100.3600/69.M3100 is white on steel, 03.3100.3600/69.C822 is white on rubber, 03.3100.3600/21.M3100 is black on steel, and 03.3100.3600/21.C823 is black on rubber. Check the suffix against the dial and the bracelet or strap on the watch.
The central chronograph hand makes a full turn in 10 seconds, so test that the chronograph starts, stops and resets cleanly with each pusher. The ceramic bezel is virtually scratch-proof, but the polished steel case and bracelet are not. The date window sits at 4:30 and matches the dial color. On the bracelet, aBlogtoWatch would have liked a micro-adjust clasp, so check that the folding clasp closes securely.
Buying or selling a 03.3100.3600/21.M3100?
Moda is always buying. Text photos to (605) 521-2821 for a fast offer, or start on the Moda Watches page. For any deal with a stranger, Moda's middleman service inspects the watch before money changes hands.
Common questions
What movement is in the Chronomaster Sport?
The El Primero calibre 3600, an automatic chronograph that beats at 36,000 vibrations an hour (5Hz), has a 60-hour power reserve and shows a tenth of a second with its central chronograph hand.
How does the 1/10th of a second chronograph work?
Taking advantage of the 5Hz beat, the central chronograph hand makes one turn every 10 seconds instead of every 60. The one-second mark sits where the ten-second mark would be on an ordinary chronograph, so the bezel track reads in tenths of a second.
How big is the Chronomaster Sport?
The steel case is 41mm across and 13.6mm thick, with a lug-to-lug of about 46.2mm according to aBlogtoWatch, and it is water resistant to 100 meters.
What is the 03.3100.3600/21.M3100?
The black-dial Chronomaster Sport on a steel bracelet. The /69 reference is the white dial, and the C822 and C823 codes are the rubber-strap versions.
Is the bezel metal or ceramic?
Black ceramic with an engraved 1/10th of a second scale. Monochrome Watches notes that it is virtually scratch-proof and impervious to UV rays.
Related references
Sources
The facts on this page come from the brand and from established watch publications.