So as Ive posted recently i launched the Rambler. Very happy day indeed. I did so with a salvage prop on her. 12.5 diameter. A bit unsure of the pitch, might be 11. It is cupped. Old Chris Craft prop.
She made a hair over 6 knots. This was confirmed at slack water both into and with the wind. Shed only pull 2500rpm. Westerbeke W13a. Governed at 3000rpm.
I spoke to a prop shop and they are suggesting a 13x9 or 13x10. I can run a 13 diameter prop without clearance issues.
The salvage prop is quite pitted and the edges are eroded as well, so not the best test. I have read that the correct wheel can make quite a difference.