Props for salt water or fresh water performance ???

d6moff
By d6moff,
Hello, Has anyone noticed a difference on performance when comparing salt and fresh water? I have a 2008 chap 215 with a 270hp VP and in the two 2 years I have owned it I have never had it past 4200rpm and 41mph, The boat came with a 19p 4 blade VP prop, I have also tried a 20p & 18p 4 blade Michigan wheel props but very little difference on performance between all 3. Mechanically I have carried out various checks fuel pressure, compression and everything is as it should be.....when I bought it I had issues with it due to dirty gas but these should have all been resolved now. I have now been informed by a very experienced old boater that I need to drop my prop size further to get my rpm up and thus up my speed,. Due to being in fresh water and its property differences from salt he reckons he always used to stock two props for his boat one salt one for fresh. He suggests that due to the lack of salt my boat sits too low in the fresh and needs the smaller prop for lift (which I understand) but he also said when we went for a run that my engine was loaded out with the larger 18p x 14.5 , 4 blade prop due to the density difference of salt and fresh and I need a smaller prop to push the boat?? Now I was on the forum previously and all the 215 SSI owners were running around 19p -21p props....are you guys running these on salt or fresh water... I honestly think I will never get the factory performance out if this boat.....and yes all other variables such as fouling, hub slipping, weather, weight and GPS have been checked \considered....this man swears my prop is too big for fresh water use....interested to hear other people's experiences..