Maybe you can help (I don't trust local service centers in Ukraine). My watches fell down and now when I pull out the crown nothing happens, I can't adjust time/date etc., the first action (pulling out the crown) works fine, second hand moves to correct position (whichever it is), but when I rotate the crown nothing happens. There is no visible damage to the watches, other buttons work just fine. I decided to disassemble the watches and it got even worse...now the sound is gone and my time zone switched to TYO (which is default I think), time remains the same, but I guess the year has switched because date is correct but day of the week is not. I only unscrewed the screws, removed the cover, understood that it's a small piece of space technology and then put the things back. I will visit local service center in Kyiv but I have doubts that they've ever seen Casio Oceanus here because the most expensive Casio I saw in local store was around 50$.
Maybe some of you have met same issue before and will be able to help me? Maybe there is a way to change the time zone by interacting with the buttons/holes under the cover? There are a lot of them (I don't think I managed to find a manual though).