Kiwi prop --- feathering
I can help you with this one.
I live here with them!
The Kiwiprop website is unfortunately the very best part of the kiwiprop.
I was all set to buy one sight unseen when I was finally talked out of it by a couple of knowledgeable sailing friends and the guy at the boatyard. I finally manged to find one to look at, and while they are a nice idea...they really do seem to be FRAGILE...and that is not a word I want to attch to my feathering prop.
The independent swing of the blades is a nice sounding idea..until I saw how they achieved it. By the time I had stopped twiddling with one I was ready to buy the poeple that had stopped me from sending my check a drink.
A week later I went with the Autostream, all stainless, feathering prop. This thing is bloody amazing.
The price is higher (though not that much), but the longevity and reliability is miles ahead.
The most relevent issue though, was the weight difference. The kiwiprop is a lightweight! a 24inch prop weigh less then 2kg...there is a lot of plastic in it (also, to gie it some credit, a lot of Vesconite...which is an incredibly tough plastic that outlasts steel in some applications). The Autostream that we bought for our boat weigs in at 7 1/2 kg before it is pumped fuul of grease and such. It is CHUNKY.
But it is also a lot more efficient. The kiwi uses thin plastic blades and needs to broaden them to allow the steel rod that attaches them to the prop hub. The Autostream uses all stainless contruction and has optimised blade shape.
The other prop you may want to look at is the Tri-stream...a folding three blader that is pretty amazing.
Hope that helps.
By the way, our boat is a 2.6 ton 27 footer...and the kiwi still felt too fragile...