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  • Casio Oceanus OCW-S100-1AJF

    Frank W

    There aren't many small radio-controlled solar-charged watches available that have a classic look to them. Most of these watches are larger, have busy dial and tend to be sportier watches. This Oceanus is a nice exception from the norm.

    The actual size is smaller than the official numbers by Casio suggest. At 39mm, it is a great size for small and lager size wrist. The height is 10.7mm but that includes a slightly domed crystal. The actual height from bottom to top of bezel is about 9mm. The very low weight of this all titanium watch often makes you forget you're actually wearing a watch.

    The case and bracelet have a titanium carbide coating which makes it much more scratch resistant than regular titanium and stainless steel. The bracelet and clasp on mine have some light marks and scratches from desk diving. However, the bracelet is lightly brushed so they blend in. Adjusting the watch when travelling to a different time zone is a snap. Just pull out the crown and point the seconds hand to the new time zone on the dial.


    This Oceanus has a shock-resistant Tough Movement movement which is proudly displayed on the dial as Tough Mvt. Solar charging works great and keeps it charged sitting on my desk during the dark winter months. The radio-controlled time sync works in North America, Europe , Japan and parts of China.  I live in Michigan and it has no problem picking up the signal from Colorado.

    Time sync during a vacation in London and the Netherlands was without any issues as expected. There are transmitters in the UK and Germany and they cover all of Europe. With the auto calendar and time sync, there is no need to adjust the watch at all. Even when you don't live with the radio controlled areas, it is still an accurate quartz watch that runs ± 15 seconds per month.

    Does it annoy you when the seconds hand on a quartz watch doesn't exactly hit the markers on the dial? Never an issue like that with this Oceanus. Even when the seconds hands is knocked out of position by external shock, you can adjust it again to make it go back to normal. The date display is larger than most mechanical watches and is easy for me to see, even with my 50 year old eyes without reading glasses that I normally use when reading.


    The crystal appears to be slightly tinted. This makes the dial look a bit dim in low light but still easy to see the the time. In bright sunlight when most watch dials can look washed out, the light tint brings the dial to life. The 5-minute dial marker have a blue edge. That gives an interesting effect under different angles and light and is a nice detail to an otherwise understated design of the dial.

    There are many other Oceanus models and I think they are a Japanese Domestic Model (JDM) only. This model is part of the Classic line and there are also the Manta, Cachalot and bluetooth/gps models. These watches are very different form you regular inexpensive Casio watches most people in the rest of the world are familiar with. I also have a Seiko Presage and I think the Presage quality and attention to detail is similar to the Oceanus. This isn't the average $50 quartz beater you find at department stores.

    As these are JDM only, you'll have to find these online on eBay or other Japanese sellers. They often can be found new for about $500 which makes them an excellent value with the materials, quality and technology that is built in. I bought mine from SeiyaJapan after reading great reviews on the forums. And the experience didn't disappoint. The watch I received left the factory only a few months before and it arrived within 2 days from Japan to my home in northern Michigan. SeiyaJapan is a bit more expensive than the average eBay seller but they sometimes have discount codes and I rather pay a bit more to buy from a seller with a good reputation.


    To summarize, this is the perfect daily wearer and travel companion. Its size is just about perfect on my 7.5" wrist and the style is somewhere in between dress and sporty watch. Nothing flashy but it looks and feels nice on the wrist. It feels at home on the beach and at the office. I am very picky when ti comes to watches and there are a few minor things that could improve this watch. The bracelet is integrated with the case so toy can't easily swap it out with a leather or nato strap. But perhaps that is a good thing because it's such a joy to wear on the bracelet and it just looks great. A sliding mechanism in the clasp would be nice as well. But that's about it.  

    Actual measurements with digital calipers:DSC02894.jpg.94c7d08e8af2dfa59ad9034c96266265.jpg

    Case and bezel diameter: 39mm
    Width at 3 to 9 o'clock including crown: 43mm
    Height: 10.7mm
    Lug-to-lug: 45mm
    Lug width: 21mm
    Bracelet width at buckle: 18mm
    Weight including bracelet: 84 g

    Module: 5235
    Water resistance: 10 ATM
    Crystal: Double-domed with inner anti-reflective coating



    Manufacturer website: https://products.oceanus.casio.jp/_detail/OCW-S100-1A/
    Owners manual in English: http://support.casio.com/storage/en/manual/pdf/EN/009/qw5235.pdf



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    I am the proud owner of an Oceanus OCW S100-1ajf. Feels and looks great on my wrist, easy to read, easy to change time zones, and due to my location, picks up WWV every night. I also like the uncluttered and subdued face. Although this is the perfect watch for me, I can see why others might avoid it. If you want a watch that just tells time and date, this is a strong candidate.  If you want a watch with a lot of seldom used features, buttons, sounds, and displays, then this watch is NOT for you. It makes a lousy toy.

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    Easy to read...except for the tiny city information, which is tiny. It's not a bad thing because it doesn't clutter up the watch face, but if I want to read them I have to put on my spectacles or zoom in with my phone. :) Love the watch, dislike the bracelet issue.

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    I find the band to be sharp and pulls on my hair, the band doesn't look like its coated. I was wondering  if anyone else has had the same issues. 

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