: I have a 1988 Searay 300 weekender with Ni-Bral, 17x15 Cup
> props and twin 5.7L Merc Inboards. Searay indicates that the props
> should be
> 17x16 and should achieve 4400 WOT. I have replaced the tachometers a
> few years ago. So I believe that they can be trusted. My WOT is
> 3600-3800; the port engine is able to run a little higher rpm. It is
> my understanding that a prop pitch of 15 is less aggressive than 16
> and as such should allow the engines to produce higher rpm. I spoke
> to another boater with the same boat who has 17x16 props and gets about 4200 rpm.
> Is it possible for my props to increase in pitch without causing
> noticeable vibration? Also, both props appear to have signs of
> cavitation pitting.
