I have a 2007 ranger banshee with a 2007 etech 50hp, jack plate and trim tabs. In smooth water it planes fairly quick and WOT is 29 @ 5400 RPM 2 anglers, full tank, gear and cooler. In anything other than smooth water the prop will cavitate at times for no reason. I can hear the engine change in sound and look at the water pressure gauge drop. if I slow down to a crawl it will go back to normal or if I turn hard left or right it will hook back up. Trimming or jacking has no effect. Motor is jacked all the way down and only trimmed slightly when it happens. Currently have a Viper SS 3 blade prop - 13 7/8 x 17. Engine is mounted almost on the lowest hole - can go one more down - cav plate on motor looks like it's even with bottom of boat. Any help???????