Semi-planing
rgnmstr wrote:
Doug, I guess I have been semi-planing. Once last summer while under
spinnaker right before we put the pole in the water and my chute
trimmer's back got soaked. He was standing at the shrouds.
heh heh did you manage to sneak a look at the knotmeter?
Usually when the boat is going really fast, everyone is too busy to look.
... We were a
little squirrelly.
The issue for boats that don't generate much lift with their hull is
that the power in the rig drives the wedge-shape bow deep into the bow
wave, where pressure oscillates from one side to the other, sometimes
quite sharply. At the same time, the rudder begins ventilating and
lifting, generally losing effectiveness. The keel & rudder foils are
getting out of their envelope of effective lift-drag flow, lots of
turbulence & drag, tends to build up then shed quickly. The result is
that the boat starts acting more & more like a kicked puppy, scampering
in all directions except the way you want it to.
Fresh Breezes- Doug King
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