Propeller size , could someone help me out

[bobs]

Hello again gentlemen ,

by the end of the week our boat will be lifted to stay on the hard for the next 7 months . It will be stationed on one of the Canary islands .
I will try and get my propellor off , it’s been 9 years now since I’ve replaced the cutless bearing so it could turn out to be a tough job .
I intend to take the prop home and have the symmetry checked and if necessary corrected .
Also ask the shop about the specifics of the prop. , no more room for error , just the way Marc 1 likes it ��
At the same time change the cutless bearing while I’m at it .


Regards

[bobs]

Originally Posted by Marc1

Err ... let's not start name calling just yet.

So the prop is 18 or 19" diameter.
But who is to say that it is 13" pitch?
My prop is marked 18x15.
However it is neither 18 " diameter nor 15" pitch. It is 17 3/4" and 16" pitch

13" pitch is but a guess.

New development, and because Marc1 was the most skeptic I feel I need to address him with the revelation .
Finding this procedure on Youtube to determine the pitch was an eyeopener

https://www.youtube.com/watch?v=X88yfqFTbPY

Applying it to my propeller it seems the pitch isn't 13" , but .....19" , the same number as the diameter . And that could be right because having the prop off the boat at home now I was able to read the punched numbers hidden under the propeller nut , they are twice the number 19 .
So the mystery is now solved and Marc1 was right to question my presumptions.
Measuring the diameter was easy and straight forward , using the simple youtube procedure gave me an idea of the pitch and the rough calculation corresponds with the 2 indicated figures on the prop .
Knowing that , I was looking for a replacement already , I found a pristine secondhand with 18" x 18" as specs , would that one inch difference , both diameter and pitch , be a big deal on the performance of my engine ?
Does anyone have an idea please ?

Regards