Are you aware of the Yachting Monthly report on fixed v folding v feathering v variable pitch propellors? If not, that should be your first port of call.
Like all these reports, it still requires careful reading, since it was done (like most such tests) under non-real world conditions, and even then the results relat3 solely to one particular yacht.
But still, in my subjective opinion, it is clear that for cruising, it would be hard to beat a Brunton Variable Pitch, but cost in relation to value of your boat is significant.
A three blade feathering is the next step down.
Two blade folders are fine for racing yachts, bu5 less than ideal for cruising yachts.
But at the end of the day, any folding, feathering, ariable pitch prop is going to increase your average speed under sail significantly, and hence feduc3 your passage time accordingly.
Parker 27/146 "Stroller'
I was going to email you a copy of the original, full article that was first published in Yachting Monthly in May 2009, but I cannot find you in the Members Handbook?
I have a 325 which had a Kiwi Prop, It seems that this type of prop is very much effected by muck on the bottom of the hull. I had an unfortunate incident recently where post Covid where the boat had been in the water for 18 months of which the lockdown period meant it did not move in the Beaulieu river for some 6 months and was heavily weeded up around the prop. On trying to get back into the Beaulieu River In a strong SWly I did not have enough forward thrust as the prop was not opening properly, consequently going aground and being towed in by the Beaulieu harbour Patrol.
I have now reverted to the original fixed prop to see how that goes, although the power in reverse does seem pretty poor.
Bottom line is that if you have any prop with a folding mechanism, make sure you have a clean bottom!!
'Kalandia' Parker 325
Moored: Beaulieu River
We had a blade damaged on lift out once which was replaced for just under £100.