Wednesday 12 March 2008

Delivery delayed

We don't have a critical deadline to meet, but a new boat is always exciting and I was starting to prepare for what we'd do running it in over the Easter weekend.  Anyway, its important given issues like the propeller choice and critical engine height that Graham Jelley (the owner of Scorpion) gets some time in it. We plan to keep it in Lymington for a couple of weeks after launch to do any snagging and try out propeller options.  Launch date is now March 28th.
PROPELLERS
My knowledge is close to zero on propeller choice, but I have been surprised in this process how people attribute many aspects of the boat's handling to the prop design (trim, stability, chine riding, going up wind, going down wind, cornering, acceleration) even before you consider speed and revs.  As we will be running with the propellor close to the surface and higher, much of the time we will go to a four bladed prop which I assume provides more grip as its going to spend a lot of time operating on the surface. We have a 3 bladed Laser 11 on our current 7.5 metre Scorpion with a 21 inch pitch and this time I think its likely to be from the Bravo range. As for pitch, I guess it will be somewhere between 21 inch and 23 inch although we have a different gear ratio on this boat at 1.62.1 compared with 1.75.1 and a Sport Master gearbox.

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