I do my share of cars that have water spots on the paint.
First try a cleaner wax, maybe the Meguiar's White Wax, has some cleaning abilities and can be found over the counter. Using a DA, if you have one start out with a white pad and the White Wax. Do a test spot to see if it removes the water spots, if not go to a polish like Ultimate Polish, if still not get the results try the Ultimate Compound. Guess what I'm saying is to start with the less aggressive. Make sure to clay first. Something else that may work is the over the counter Meguiar's Cleaner Wax, I used it a couple of times to remove water spots and worked for me. If you have more advanced products then of course use what you have, just not sure what you have on hand. Good luck with it, keep us updated. Shoot me an email if you have any questions , you can call me also once you email me , I'd be happy to give you my cell:dblthumb2: