HEY GUYS!  GOT A WORK PROJECT TO FLY OVER A POOL OF WATER SEARCHING FOR A DECANT PIPE IN THE POOL AREA!  
ANY ADVICE WILL BE GREATLY APPRECIATED!  FROM WHAT IVE READ IF I DONT FLY TO LOW (less than 25 meters) I SHOULD BE OKAY?
THOUGHTS?  

THANKS AGAIN,
TCDrone

Flying over water is not an issue.
BUT you need to make sure you are in control of the drone as the bottom sensors will be fooled by the reflective surface.
Keep an eye on the drone at all time to be sure.

I have flown many many miles over water with my MP.
Very low (< 50cm) even.
No issues except for the drone that sometimes thinks it is flying very low or high and decides to raise itself (or lower itself....).

Captain Montfrooij,  Thank you very much fo the info!  Greatly Appreciated!

Hi. Thank you for reaching out to DJI Forum. With regards to this inquiry as Montfrooij said at post #2. The sensors may have difficulties in determining the surface of the water due to the water reflection, reflecting on the vision sensor of the said drone. For reference, I will be posting an image on steps how to properly use the downward vision sensors. Thank you and safe flying.