Prompted by the plans request, I got my old Waverider out again last weekend. It had had a midlife upgrade about 10 years ago - the old (unsilenced) Frog150 had come out and a (silenced) Merco35 had gone in. It currently has a X45 prop on it.
Last weekend after some fettling it managed about 21mph (real speed) which looked pretty fast but is probably quite slow for a fast model boat. But I have no idea really.
So... can anyone help me with....
a) What real speed a Waverider should be able to achieve (mine porpoised very badly at full throttle with the Merco and so I have had to fit some aluminium 'trim tabs' to the transom to get it run flat)?
b) what prop should I have on an old Merco35? From the sound track, the engine is turning just under 10,000rpm (9960rpm as per spectrogram on audio track) which suggests a smaller diameter prop is required.