18’ Seagull Catamaran 50hp Yamaha 4 stroke. All my props are 12” and aluminum. 3 blade 9 pitch horribly hole shot lots of cavitation top speed 21mph. 4 blade 9 pitch a little bit better hole shot 19mph. I was told I need an 8 pitch 3 blade? The same as a pontoon boat? I was also told I need a...
