I have a 2011 Bennington 2275GCW with 150 HP Yamaha and elliptical pontoons. I have had cavitation issues with this boat since the day I bought it 6 years ago. Have had 3 different props on it, no change. Cavitation is worst with 5 or more people on the boat and if the water is at all choppy. I have used all combinations of trim and seating configuration (moving bodies around in boat). Nothing works. Dealer gave up on it after 3rd prop (I paid for all 3!!!) and could never replicate the problem because they only had 1 or 2 bodies on board. I don't understand why, but it occasionally occurs on our outward part of the trip but occurs almost 100% of the time after being out for hours (low speed) and then powering up on the return trip. While the boat will go 38 mph top speed, it will start to cavitate on anything over 10 mph or even less - 7 mph. Thus if I go out 20 miles, it takes me over 3-4 hours to return. This is extremely frustrating and very embarrassing with passengers on board. I am at wits end on what to do. I only take the boat out 2-3 times a year because of this issue. In my 6 years of owning this boat, I have never had a day on the lake or gulf of mexico with 4 or more passengers when this did not happen.