Getting here
I was asked recently, ‘What got you into designing?’ To which the honest answer is ‘foils’. Early in 1977, aged just 19, I was sailing
with Phil (Pod) O’Donnell and Donny Hanks on Singapore Airlines, which was quite possibly the first Kevlar/foam 18ft skiff, before wings and stupidly light, probably lighter than a 49er. There was a ‘stiff’ southerly, we had
come around the Double Bay mark head- ing into Taylor Bay, I was in the beak (forward hand), spinnaker on, and we had some pace on. It was said that we were doing well over 30kt, but I discount that, because it was way above the then recog- nised world speed record.
64 SEAHORSE Pod had already won an Olympic gold
medal in Kiel sailing Dragons with John Cuneo in 1972. He was not an idiot. But halfway down that run it all went pear- shaped and ended in tears, lots of them. After the race Pod was bitching in the
park about the rudder, and I stupidly said, ‘I reckon I can do better.’ He looked at me and said, if you can, I will buy it and sing your praises, if you can’t, you wear it! I had a week to put up or shut up. To cut a long story short, within two
years we were making 90 per cent of all the foils in the 18ft fleet. Within five years it was 100 per cent plus most of the other skiffs… and probably half of the other dinghies racing on the harbour. Truth is that 99 per cent of sailors read
about a hull and then flick immediately to the rig. They rarely spend much time or interest on foils at all. Yet if you think about it a bit more
closely, there are only two things that make your boat go forward and they are, to use one of my father’s favourite lines, ‘the foil in the air, and the foil in the water’… to which he added ‘and a bit of low-drag flotation in between’.
My stock response to people, when they
ask me what I think sailing is, is that it is ‘the exploitation of the velocity differences of two mediums’. And if you’re a devotee of Newton (and if you’re not you should be), for every action, there is an equal and opposite reaction. So by definition the foil in the water is
equally as important as the foil in the air. And relatively speaking… whereas a change of 2/3/4mm is important with respect to the rig, 0.2-0.3-0.4mm is impor- tant with respect to your foils. Why? The most common response is
water is more dense than air – correct, 812 times denser approximately. But, far more importantly, water is incompressible (whereas air is very compressible indeed). Having helped Dad [Frank Bethwaite]
with wind tunnels and doing all that research I completely get why a naval architect goes and grabs the NACA book of wing sections – the one on my shelf beside me was published the year before I was born – because it’s so easy to do. And 90 per cent of the time it is a mistake. We learned in 1976, with the K1
women’s kayak event at the Montreal Games, that the K1s were always faster in the St Laurence Seaway (10m+ deep) than they were on the Olympic track (4m deep). If a 60kg woman, with a 12kg K1, doing 19kph (9kt) max is suffering surface effect at 4m, then imagine the disturbance that a 250kg 49er (including crew) doing 9-11kt
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