I am currently trying to run a Monte Carlo RNG method using arcGIS. I am wanting to select all water bodies within a map, say northern Ireland and I would like to then somehow select every body of water and then tell the monte carlo code not to assign a random number within this region (all bodies of water). What is the best way to go about this method? This is basically to start the geoselection process for a new fleet of nuclear power plants, and of course, they cannont be situated within bodies of water so there should be no data points within water body regions. Is there a tool that will automatically select all water bodies? or is there a pixel colour registration that I could implement i.e blue pixels correlate to pixel number#43242 etc. any feedback or advice will be greatly appreciated.