Hi Dave,
Yes with you and Mr B re. thrust calculation it's not going to make a lot of difference - fitting the wrong prop could be a lot worse !
We did find on the revamped big 31, flattening the shaft angle helped/stopped any porpoising running on flat water,
remember the dreaded Ali trim tabs guys bolted to their transoms in the 80's/90's?
Interesting 'Fairey story' I would love to get to the bottom of -
chatting to a gentleman watching the club stands offshore racing videos from the 60's with the Fordspeed team at Warwick.
He reminisced about his parents owning a grand house up a river off the Solent, who were friends of the Twiss family,
and Peter Twiss taking him out for rides on a gas turbine powered Huntsman 28 !
He had vivid memories of the boat being silent when it approached and a loud whistle/roar when passed by.
Not managed to find anything re a Fairey gas turbine cruiser, aircraft is of course another story, you can imagine how it might of happened -
the worlds fastest pilot/driver/cabin cruiser salesman, one or two spare gas turbines taking up space in the factory stores ???
the mind boggles.