I bought mine thru Amazon, and the instructions were in Japanese also. Good thing I was able to download English version. Thanks for sharing the website for English language manual.
The instructions and the website do not say that it is water proof. It does say you can wash it off with water if it gets dirty. I wouldn't recommend putting it underwater. Here is the product website. Hope this helps. www.cateye.com/intl/products/computers/CC-VL820/