For a long time I have been wanting to install a propeller that had better performance when I wasn't using the engine. Yes, my 2 blade fixed propeller was a big source of drag when sailing (in the order of half a knot). I looked at both folding props (the blades fold away when sailing) or feathering props (the blades turn and feather into the flow presenting a smaller profile) to reduce the drag.
After a lot of research I decided on a feathering prop since it would give me better performance when motoring, better performance in reverse and less likelihood of the blades seizing up in their off position. The big negative being cost.. All the brass feathering props were over $2k, until I found the Kiwiprop from New Zealand for about $1,200. It uses composite blades (same material as aircraft blades) and reduces vibration because the blades are lighter. Practical sailor as well as all the sailing forums recommended it highly. Done.
Thought I would need a prop puller to get the old prop off, but it was a already loose because I had put in a new shaft a couple of years ago.
I removed the old zincs and cleaned the propeller shaft well
Installing the kiwiprop which was tailor made for my shaft was very straightforward
Finally I painted the Kiwiprop and shaft with Propspeed which should prevent fouling. I heard that composite blades were less resistant to fouling because they didn't contain copper and so was wary of the feathering blades seizing up due to marine growth.
The kiwiprop works great. The boat moves faster forward at lower revs, vibration is reduced and it packs a punch in reverse! So far so good, I would recommend the kiwiprop.