First off, I know changes in alt and pressure affect either reading, but mine is so far off I can't calibrate my pressure. I did a quick search in forums, but I'm on my iPhone and can't figure this riseman out. I drove and dropped 1700 ft in 1 hr, and my watch is all out of wack. The pressure is out of normal range so it just displays dashes now, and it won't let me calibrate the pressure. I'm confident altitude is accurate. I know the manual says pressure readings will show once back within normal limits, but I can't calibrate anything and I won't be gaining my altitude back. Any help is appreciated.