Growth on Prop

[FreeBeeTony]

How much performance would one lose with a prop like this?
My boat was stagnant for ~ 6wks.

MOD EDIT - FIXED 1 PIC SINCE THEY ARE THE SAME

 

[ondarvr]

Interesting pics

 

[tpenfield]

How much performance would one lose with a prop like this?
My boat was stagnant for ~ 6wks.

Just like the pictures say . . . 100%

 

[FreeBeeTony]

I went from 30MPH @ 3600RPM to ~25MPH @ 3600RPM.........a loss of ~5MPH.............

 

[ondarvr]

Since we can't see the pics, I can only say that it's easily possible to lose 5mph.

 

[Scott Danforth]

Friend of mine took his boat out and just putted along downstream. When he went to turn around, the barnacle growth was so bad, he couldnt come back against the current. He had to drop anchor and get a diver to chisel the barnacles off the prop.

 

[tpenfield]

(1 - 25/30 ) x 100 = 16.7% loss

I assume salt water . . . Best to paint the prop with anti-fouling if it is going to be in the salt for weeks at a time.

 

[StingrayMike]

I would be concerned about growth on the boat as well. That will defiently slow you down

 

[FreeBeeTony]

I would be concerned about growth on the boat as well. That will defiently slow you down

I agree.........going to check this w/e.
Cleaned up prop and repainted. Installed and tested last night. Picked up ~3MPH but still doesn't seem right...........Like its plowing. Trimming doesn't help.

 

[Texasmark]

I would be concerned about growth on the boat as well. That will defiently slow you down

+1 on the hull drag increase. Doesn't take much growth to have a huge impact on performance. BTDT

 

[jimmbo]

The hull is most likely the same as the prop. I never left my boats in the water for more than 2 weeks and then it was Scotchbrite time for the hull

 

[anonOmattie]

how much performance will you lose with growth on the hull?

 

[tpenfield]

how much performance will you lose with growth on the hull?

All of it . . .

 

[jimmbo]

how much performance will you lose with growth on the hull?

Fresh water growth feels slippery but will knock several miles an hour off the top end. I don't even want to imagine what Barnacles in salt water would do.

 

[jsparks747]

It is amazing what growth on the hull can do. Had a boat in Port Townsend that looked like someone was trying to start a mussel farm on the hull. The prop shaft wouldn't even move after that cleaned off all the barnacles and rust.