Prop diameters

[ReneT]

Hi,

I'm new to RC boats and I have been looking at props and their numbers. As always anything can be found on the internet, so I found what the numbers mean, but i have one last question:

If you have two props with the same total pitch, what is the difference between the two?

Example:
Octura 445: 1.4" pitch * 45mm diameter = total 2.48"
octura 542: 1.5" pitch * 42mm diameter = total 2.48"

To me they are interchangeable, or am I missing something?

[dasboata]

the prop with , more diameter will be faster, where are you getting the 542 number from I could not find a octura 542 on there 2013 chart ? or just using it as a example? I have had better results with larger diameter props, on my SAW gas cats !!