Brian,

This might seem like a lot, but when you have to get a puller in there
to get the prop off the shaft, that may even be a little tight.

There is also shaft and bearing service to consider here.

I also knew of two hull of the same class and one had the propellor
about centered in the aperture, the other had less than an inch forward
clearance. They had both had shafts replaced....

Then there is still the issue that the builder may just have choosen to
make the aperture large (it was written many places that this makes for
less rudder vibration under power - I don't agree). Builders (by
enlarged) make what is most effective for them to build and sell.
Seldom does competitive performance enter into the equation. This is
why service is available to re-fair keels and rudders.

If you wanted to plug it to improve the rudder effectiveness, go ahead.
Just make the piece removable (and do your best not to leave hard
edges at the leading edge that will cause turbulance on the low pressure
side).

Matt Colie

Brian Cleverly wrote:
Matt Colie wrote:

Brian,

I was reminded in a design class that it was a resonable idea to allow
enough room to remove the prop without removing the rudder or engine.
Even on long keel boats, propellors sometimes take damage.

Matt Colie


I agree, but that wouldn't require the approx 6" additional clearance
this boat has.

Brian C

Brian Cleverly wrote:

Does anyone have any thoughts/theories on the reason for extending
the prop aperture into the rudder when the rudder is hung off the
back of a long-keel.

I would imagine it would drastically reduce rudder efficiency, but
possibly allow more of the prop to receive undisturbed water when
backing-up.

Thots anyone ?

Brian C