The Gori Propeller
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Believe it or not the propeller is an engineering
marvel. A standard propeller causes so much drag on a boat while
it is sailing that it can reduce the boat speed by a knot or so.
If you think that's insignificant then consider that 120 nautical
miles is a good day's cruise for a boat like Sister.
That means she's averaging 5 knots for 24 hours. If the propeller
drags enough to reduce boat speed by a knot then you'll only make
96 nautical miles under those same conditions. That's a 20% hit
which would turn a 10 day run into a 12 day run or a 20 day run
into a 24 day run. That's significant, particularly if you're
the one making the cruise.
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Sister's propeller has three blades. The blades are attached
to the main body of the prop by a mechanical system that causes
the prop to open up in one direction when the shaft is turning
"forward". Putting the boat in reverse causes the prop
to fold then open in the opposite direction. Most importantly,
when the shaft isn't turning, that is when you're sailing, the
prop folds into a sleek shape that causes minimal drag. If any
of you make an extended passage with us I know you will appreciate
the Gori propeller.
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The Three positions of the Gori propeller
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Here's the propeller open in position to drive
the boat in one direction. |
Here's the propeller open in position to
drive the boat in the opposite direction. |

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And here is this wonderfully accommodating
propeller folded to minimize drag. |
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