[Public-List] hull speed

[George Dinwiddie]

Jeffrey,

On 11/14/11 6:45 PM, Jeffrey wrote:
> Gordon,
>
> With respect, I don't think it is possible to power an A30 hull to 7-8
> knots. Hull Speed is somewhere around 6.2 knots. My 20hp can power the boat
> to just over 6 knots at max rpm, but the noise and fuel consumption is
> wicked. I've hit 7 knots and more for very brief periods of time under sail
> when hit with a gust, but never under power. These speeds clocked with GPS.

Oh, you can go faster than hull speed.  It's just that the power 
required to do so goes up quite fast as the boat starts climbing it's 
own bow wave.

I've been on an A30 going in excess of 10 knots (sometimes pegging 12 by 
the knotmeter), but they get pretty squirrelly with that much of the 
boat out of the water.  This was night-racing on Kittwake in 40+ knots 
going wing-and-wing with a reefed main and the #2 genoa poled out on the 
spinnaker pole.  It tore the spinnaker pole track off the front of the 
mast and the tiller head twisted off the rudderpost twice.

And ask Mike Lehman about the 10 knot spinnaker deathroll.

  - George

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