Frank Bethwaite, the father of High Performance Sailing, dies at 92

by Richard Gladwell on 12 May 2012
The highly regarded designer, meteorologist and sailing scientist, Frank Bethwaite died in Sydney, Australia, this morning. He was in his 92nd year.

Capable of intensely complex analysis, Bethwaite was without peer in the science of high performance sailing – which was best defined as boats which could sail faster than the windspeed.

An intensely serious, focused and loyal man, Frank coupled a very intense analysis approach with the ability to think laterally, and this created the genius that was Frank Bethwaite.

Frank described himself as having a 'professional background in aviation associated with science and meteorology'.

Frank melded a very sound understanding of meteorology, with an innate understanding of boat and rig design, the elements involved and how they interacted. Coupled with that was his ability to test and develop a scientific basis for testing, together with his ability to quickly build and modify test boats and rigs, so the whole learning process continued in a steady and studied manner.

This process led Bethwaite to discover and measure the ranges of factors on the interactions between hulls, rigs, sails, wind and waves. He found out how to make rigs work in response to changes in wind strength and pressure, so that the effect on boat performance and crew was smooth.

'I have always found it rewarding to measure what I could reasonably measure,' he wrote.

In the 1960's a low speed test platform was developed consisting of a beam across the back of a small motorboat, which was used to tow pairs of hulls at varying speeds and with a measuring device fitted into the tow, so that the drag of the two hulls could be measured, and compared, at various speeds and weights in the boats. These sessions could continue for up to ten hours, taking advantage of changing sea conditions with a constant test rig.

Then in the mid-1980's a more complex, but more accurate measurement method was employed which incorporated GPS.

The data collected led Frank to conclude that there was a significant difference in drag between hulls that looked the same but were subtly different in their shape, resulting in marked difference in the drag of each for a given towing speed. In a series of articles in 1999 and the development of the 29er he called this phenomenon the 'dynamically humpless hull' - a reference to the fact that such hulls had smooth drag curve as speeds increased and were much faster, compared to those who had a wavy or bent curve and had a 'speed or drag hump'.

Frank wrote of the 'dynamically humpless hull' – 'because nobody knows what makes a hull 'humpless' it is a case of 'try it and see'. This statement probably typified Frank’s approach in that everything had to be capable of being proven by factually based analysis.

As an aside, many of his ideas and theories did not work when tested, and the key was analyse and change direction if need be, and always continue the learning process. Mistakes weren't errors, just a point where you had to change direction, or re-evaluate your thinking.

Of course, in sailing, the drag Frank measured on the tow platform co-related into the power needed to propel a sail boat and determined the speeds that were possible to attain. Simply put, low drag hulls were faster for the same sail power, than higher drag ones.

Maybe it was in deference to his aeronautical days, but Franks' real thing was foils - the ones that went in the water, and those that worked in the air. His favorite line was 'a foil in the air, foil in the water and a bit of low drag flotation in between.'

The sum of this knowledge was laid into the prototype 49er, designed by Julian Bethwaite, which was selected by the International Sailing Federation as the Olympic skiff in 1997.

Similarly with the smaller 29er, which was put through a much more intensive and extensive process by Frank and others to optimise its sailing performance, ability to be easily righted, be tolerant of modern crew weights and a variety of factors which came together in the one boat.

In discussions with Frank early in the 29er development process, when he went to several countries to talk with sailors and others about what they would like to see in a boat like the 29er, he made the interesting observation that the most successful boats were the ones that had the widest number of uses. He cited three iconic boats – the Laser, which could be used by Olympic sailors; used by club sailors; used as a recreational off the beach boat and so on.

Similarly with the Hobie catamaran which again had a use a serious racer at world championship level; another use as a club racer but also with mixed crews; and a use as a recreational boat; plus a use as a surf cat. The other multi use boat he had identified was the windsurfer.

He wanted the 29er to be a similar success with its multiple uses, and this is why he worked in the intense development process – which included investigating general body-weights of the population and then designing the boat to fit. He realised from this that most boats were in fact designed for a lighter body-weight than is the case in current times, as the population has got larger physically than say 40-50 years ago.

Frank Bethwaite did not have formal naval architecture training, but like many of his era was self taught. But unlike almost all others, he evolved his thinking from a basis of science, and understanding the science through extensive testing.

His role in his latter years was not so much to design, but more to take a keen interest in the projects, and challenge the thinking or inject comment.

Only last week, the 49er FX was adopted by the ISAF as the new Olympic Womens Skiff class, astounding many that a 15year old hull design could not be beaten for speed by special, lighter boats.

Frank and Nel's company Starboard Products, evolved into Bethwaite Design from which Frank retired in 2002.

Kiwi born
Born in Wanganui, New Zealand, Bethwaite’s first boat was an Idle Along 'Merlin' which Bethwaite raced at Wanganui Sailing Club, and later in National Championships at Paremata and in Wellington Harbour.

At the outbreak of the Second World War, Frank joined the RNZAF (Royal New Zealand Air Force). After graduating from the first intake of pilots, he spent two years training other pilots, before moving in to a test pilot role. In the last two years of World War II he flew Venturas on bombing operations in the Pacific, attaining the rank of Squadron Leader and being decorated with the DFC (distinguished Flying Cross)

After the War, Frank continued his flying career with Tasman Empire Airways Ltd (TEAL) which after a merger became Air New Zealand. He became a Captain with TEAL in 1955.

Frank and his wife Nel, who he met during the War and married in 1945 moved to Torbay on Auckland’s North Shore. Frank initially continued his boyhood passion for model planes developing a remote controlled model glider that set a world endurance record of 9 hours in 1952. He showed a persistence to prototype, learn, and succeed that remained with him for the whole of sailing design career. Development of the remote glider took place over a five year period.

Frank could not sail his IA at Torbay, but did buy a Cherub class designed by John Spencer, who had a shed in the next bay south, Browns Bay, and was one of the leading design innovators in New Zealand at that time. Spencer was known as the 'Plywood King' because of his predilection to design lightweight, hard chine dinghies especially for the then new plywood medium. He was almost the complete opposite to Bethwaite in his approach to design, however the outcomes were similar.

Four children were born in New Zealand, Christine, Mark, Julian and Nicola after which Frank joined the CSIRO, in Sydney, to run the flying operations for cloud seeding to produce rainfall. The family settled in Northbridge with the two older children (Christine and Mark) sailing VJ’s and Frank and Nel continuing with the Cherub.

Frank designed his first boat, the Northbridge Junior, a scow with a single sail and flat deck.

That led to approaches to develop what became the Northbridge Senior, 14ft dinghy with the same sail area as a Cherub. The NS 14 was an open design class rather than a one design with many differing designs being built over the next ten years.

For his role in the construction of the new clubhouse at Northbridge, Frank was awarded Life Membership of the Club in 1965.

In 1968 the cloud seeding project had its funding cut and Frank, then aged 48yrs, made the decision to move full time into the construction of dinghy masts, foils and boat construction. Starboard Products started first as a backyard operation before moving to Naremburn.

Eldest son, Mark was selected to represent Australia at the 1972 Olympics in Kiel, Germany, and Frank became meteorology adviser to the Australian team. That role led to meeting Ian Bruce (Canada) whose company had produced the Laser, and after a six month period in Canada, Bethwaite developed the Tasar, a two person boat for crews that weren’t lightweight. The class became popular internationally and over 3000 were built, and the class is an International Class recognised by the ISAF.

Mark Bethwaite was again selected for the 1976 Olympics in the FD, and Frank again travelled with the team as Meteorological Adviser. The data gathered in the course of that regatta became the genesis of Frank’s definitive book High Performance Sailing. Nicky and Julian teamed up to win the Cherub Worlds that year in Adelaide sailing a boat with an over-rotating rig developed by Mark and Frank in the NS14 and Tasar.

Julian continued his sailing career in 18ft skiffs, with a number of significantly different and innovative designs and developments, that saw high performance sailing knowledge progress spectacularly.

In 1997 the 49er was developed largely by Julian but with assistance from Frank and won the ISAF trials to become the first Olympic skiff making its debut in the 2000 Olympics in Sydney. That boat in turn led to the development of the 29er, intended as a two man youth, womens, adult boat. It was designed over a much longer period, as the hull and rig were carefully refined in a program run in Australia and England.

Frank's final projects included the development of a sailing simulator based around having a sailor hiking in a Laser and with the performance being measured with the objective of developing a near perfect sailing technique as a coaching and development aid. The top on the water Laser sailors produced the best numbers on the simulator.

Frank Bethwaite also updated his book, High Performance Sailing, first published in 1984 and last updated in 2008 and republished under the title 'Higher Performance Sailing – Faster Handling Techniques'.

High Performance Sailing is regarded by many as the definitive work of sailing speed.

Like many of the great thinkers in the sport Frank Bethwaite trod in the dual worlds of aviation and sailing. In a brief discussion of the units of measurement in High Performance Sailing he wrote' Naval architects tend to draw bows to the right. Aeronautical engineers tend to draw noses to the left'.

Frank drew his bows mostly to the left.

Parts of this article were adapted from www.bethwaite.com