Yesterday, when leaving the Three Prong area on Ross Barnett, I was headed south and encountered a boat head north that appeared to be determined to run into me... I kept easing further and further to the right, and he kept moving over too, almost forcing me out of the channel. I finally decided that he was bound and determined to cut to his left in front of my boat, which then caused me to have decide to drop off plane, or swing out to my left and hope that I was guessing correctly... All he had to do was keep to my left, and then cut in behind me... The strange part was the look on his face, when we narrowly avoided a collision! I know he saw the big white boat with the guy in the bright yellow shirt coming right at him...What makes folks in boats loose all common sense when they are on the water?