This is my 3rd different suunto model I have owned over the last 10 years or so, a vector, S6 and now this. The logbook function is very inaccurate. It goes through batteries too fast. Finally, I dropped it while putting it on my wrist, a height of a few feet off the rug, and it broke! I was getting ready to replace it because I need an accurate log book/altimeter for what I do, so it breaking was the final straw. I would recommend a vector over this one!