The V11 version that set the world record had a design displacement of 95kg.  It was 7.2m long and had almost round sections.  

I raced my own V11 in the 2008 Murray Marathon:

 It was not until the V14 version that I trialed the flat bottom.  It was only 6m long and the hull was 3kg lighter.  For same power input it was around 0.5kph faster than my V11.  At design stage I expected it to be imperceptibly slower based on the drag calculation but I assumed the same weight.  There was also weight saving by using a carbon drive frame.  And further drag reduction by use of dipping rudders.  Under real race conditions I averaged almost 1kph faster in the 2012 MM.  It was also fitted with the first folding prop that mostly overcame weed issues.

http://www.rickwill.bigpondhosting.com/V14_Port_Bow.jpg 

The V11 and V14 version were produced with the 7 parameter hull optimising function while I am using the 32 parameter hull function on the V16 series.  There are a couple of benefits with the 32 parameter function.  It will produce variable side flare to increase volume in the middle without increasing maximum beam. It will produce a transom at higher speed to length rather than the constraint of the canoe stern using the 7 parameter function. 

Few people realise that a 3 panel flared section does not have much more wetted surface than a round section.  The lowest wetted surface is with a flare angle of 28 degrees and the wetted surface increase is only 5% more than a semi-circular section.  So a hull with flared ends and near vertical mid sections gets benefit of reduced wetted surface as well as reduced maximum beam.  A good portion of the V16 hulls end up with deck at constant beam despite the chine being a continuous curve in the horizontal plane.  The wave drag is a function of the maximum beam squared so there is a significant benefit in keeping it low from the perspective of wave making.

Rick

Rick 

• Privacy • Unsubscribe • Terms of Use