so i calculated my prop slip, (http://go-fast.com/Prop_Slip_Calculator.htm) and i came up with 18%, is that good or bad. Its a deep-v, 30' boat single engine. Is there anyway to adjust the slip to lower it if 18% is too high. Thanks

What boat ? what drive hight ? what drive ? what prop?

And yes there is .........but do u need that ????.......
mypoint is some boats like higher slip and some don't !

Mine is 21%

Big single engine boats generally have higher prop slip numbers. Higher propslip also puts less stress on the drive.
18% is high, but not not so high that you should make any extreme changes, IMO.

What prop are you running?????

i have a bravo XR with imco 2" shorty, and a 28p bravo 1. Its a 1994 conquest enforcer 30'

What can I do? I have a 28' Pantera with speedmaster IIIA with 1.50. I don't know the drive hight, but I was told it was conservitive. According to the prop. calc. I have a 28% slip. 33"pitch, 1.50, 5700RPM, GPS 86mph; prop is merc. 4 blade. I don't know the degree of rake?

mine are at 14%

What is the drive?

I am at 15%, 100mph, 6000RPM

Imco SC Extreme -1
Bravo 1, 32" Labbed (assuming 1" less, so 31")

The rake is more likley around 13 degree.
I would actually stick a #4 on your boat with a 2 inch spacer ,,that will raise the drive up by 4 inches and give u better speed,,then ofcoarse u need to find the right prop .
But maybe yours would work too ?!
U can get the prop worked,,,,more cup and thin it ,,that would give u more bite ,,,in most cases less slip.
also if it is a stamped 33 merc, its more likeley a 35 pitch ,what diameter is it,,u can play with that as well and loose some slip. the single engine boats like around 17-17.5 diameter, my guess is u run a ~16 with that pitch so u burn holes in the water?! Mine is a 17 X 29.5 @ 6800 with a #4 ( 1:68 gear ratio ) .
Hope that helps.

I take it the prop is working good for you Phil...


I am about 5% on the stinger, even though nobody believes me about it.... 18 isn't too too bad, but i think the 15 16% is where people like to sit...
John jr