What’s in a name? Sometimes a whole lot! There are some great model names in the annals of watch history like Speedmaster, Submariner, Sportsmatic and Snorkel….but there’s one that takes the cake: The Croton Chronomaster Aviator Sea Diver. This name has all the bases covered! Fortunately, it’s not just a cool name, this is one cool watch as well.
The Chronomaster made its debut in 1963 and continued production until about 1978. Most variations are a two register chronograph with subdials at 3 and 9 o’clock, and a sixty minute elapsed time diver’s bezel. The first generation style like my example here with the large arrow hands was made from 1963 to about 1970 when they switched over to the classic ’70’s ‘stick’ hands. Mine is signed ‘Croton’, which is the name Nivada Grenchen used for their watches sold in the US. The Chronomaster can be found branded with Croton, Nivada, Nivada Grenchen, and even Croton Nivada Grenchen. There were a boat load of variations made over the years it was produced. There are black dials, white dials, some with different color subdials, and some later versions with a date function at 3 o’clock or even at 12 o’clock.
There were also a large variety of different movements to be found in the Chronomasters. The best would have to be the venerable Valjoux 23 column wheel movement, which was also found in chronographs from Heuer, Rolex and other higher-end Swiss brands. Other movements used include Valjoux 92, 7733, Landeron 248 and Venus 210 to name a few.
This example is from the early to mid ’60’s, and is the first generation style. It has a matte black dial with black sub-dials that have glossy black bevels which really make them stand out. The 30 min sub-dial at 3 o’clock has a red triangle highlighting the first five minutes which count down from 5 to 1. My understanding is that this is for timing the countdown to the beginning of a boat regatta. Because, you know, who doesn’t love to count down the beginning of a yacht race, right?
A classic lume filled arrow hour hand, dauphine minute hand and steel sweep second hand give this variation a very ‘ 1st gen Speedmaster-esque’ look. The bi-directional friction bezel has an aluminum insert marked with 60 minute elapsed time graduation, as well as 1 through 12 to double as a GMT function. The oversized crown is unmarked, however I’ve seen many Nivada branded versions that have a signed crown. The solid stainless steel case is a great size, measuring 38mm wide and 45mm long with 20mm lugs. The lugs feature a sharp bevel to them that really gives is a sporty look. Sadly this is a feature that is easily lost due to polishing. The original crystal is a gently domed thick acrylic type that completes the sweet vintage vibe. So sad when these original crystals get replaced with an ill-fitting thin new one.
This one has the buttery smooth Valjoux 23 column wheel movement powering it. As mentioned above, the Chronomaster can be found with a wide variety of movements, but my favorite of the lot is this classic V23. It’s a 17 jewel manual wind that beats at 18,000 bph, with a power reserve of 48 hours. As much as I dig this watch, it’s almost ended up on the sales block a few times, but I just can’t bring myself to part with my only Valjoux 23!
The Chronomaster is not a scarce watch, but can be difficult to find in good condition as they appear to have been a watch that saw a lot of real world wear/use. Prices obviously can vary widely, mainly depending on condition and the movement. Nice examples can range from $850 to upwards of $2000 for rarer variations. Even at the higher end of the price range, this is great value for a classically styled vintage diver’s chronograph.