The Canon – Tools for thinking about sailing and boat design – Books and Articles

Ok – there are about a million books about boat design or sailing.

However, over the years there are some that have completely changed the way I think.  I think they have strongly formed the types of boats I like to sail and of course shaped my boat designs.

The most important thing is keeping an open mind and looking for an emprical basis for information.  There is a lot of crap out there.

Also balancing published information against what happens in real life.

For example, there is a quote from Marchaj (one of the greats) that centreboard area should be 4% of sail area.  This is wrong, because if a boat is slower, it needs more centreboard area.  This means that centreboard area doesn’t actually change much in boats from 8ft with 50 square ft of sail to 16ft and 105 square feet of sail.

That is the risk of generalisation (and the net).  I am sure Marchaj placed caveats on the statement.

The OzRacer line is another case in point – from above the hull is rectangular – with only one curved line – the bottom.  My assumption was that it was a bit of a joke, a boat to be taken lightly, but for fun we did a workover using best practice for the spars, sail, foils, hull.

The boat sails extremely well and feels “right” to highly experienced sailors.  The former A class cat national champ and the father of three state champions in skiff and other classes wouldn’t come in for the Barbeque – that has to be the best empirical evidence!  Just having too much fun.

The example shows that if you understand theory, and understand practice and put both in place, then the boat will sail well even with an unsophisticated hullshape and with a polytarp sail and only costing $350 if you are good at scrounging.

The OzRacer/OzPDRacer has taught me that the bulk of the improvements in small boat performance are fundamentally cheap and easy to apply – foil shape and finish, mast/sail dynamics.  More about approach.  But racing people and most designers are caught up in thinking that MATERIALS are innovation.

NOPE – it is reduction of sail twist, accurately shaped foils, sail depth dynamics, which you can achieve with wood for $100 or carbon for $1000.

OK – so lets look at some of the resources I have found incredibly useful to understanding design, structure and sailing.  Happily a number of them are available on the net for free.

The link between all of them is that they are deeply humane – that the thing we are most threatened and limited by is ourselves and our preconceptions – that they are in the same boat (!) and you can feel their concern and love for their subject and that they know a lot more than just about sailing.

Not one trick ponies!

1/ “The New Science of Strong Materials – or why you don’t fall through the floor” – JE Gordon.

Paperback in print.

Best book on wooden boat structural design.

One of the singularly most brilliant books ever writted.  Gordon was on the tail end of high level timber technology and the beginning of composites.  He was around when the “Dislocation” theory of metal ductility was confirmed.  But the brilliant, brilliant thing is the books are absolutely wonderful to read.  Lots of discussion of archery (why the English long bow was not effective during the Crusades) why boats built by carpenters sink, how a cook on a Liberty ship made a contribution to Fracture Mechanics.

Actually I am not being fair.  The books are about bridges, wooden boats, wooden planes, why less waterproof glues can sometimes succeed in watery environments, how metal bridges copied wooden bridge structures, how composite honeycomb structures almost made aircraft designers kiss a circus proprieter , what is the fundamental flaw of traditional boat construction (don’t get angry with me – read it and find out methods to counter the problem – because now you understand it!) – and all the time you are learning more and more about design, structures and materials.  Learning by osmosis.

The best way.

2/ Structures or why things don’t fall down – JE Gordon

Paperback in print.

Best book on small boat structural design

Same as above but about structures.

3/ How sails really work – by Arvel Gentry.

Web address below

How sails really work - "slot effect" is bunkum

Gosh, this was controversial when it came out, and still occasionally is.  Basically the old theory about the “slot” accelerating air between two sails is a load of bollocks (as the Brits would say – maybe I am thinking of JE Gordon, but maybe he was way to polite for my gutter English!).

They are 35 years old now, but Arvel Gentry’s articles on how sails really work caused decades of fighting.  I read them as a 13 year old and understood them by the time I was about 15 – and my sailing improved completely – suddenly had a robust basis for why on the sloop dinghies I was racing, if I was going upwind in light winds and pulled on the main in a little puff you could point a lot higher without the jib luffing.

Basically we sailed the boats a little below hull speed (best lift/drag) and when more power was available we pointed higher.  So a gust would hit and the whole fleet would point up ten degrees to keep to the speed limit.  The boats didn’t have enough power to go faster efficiently and were very low drag so would point very high for periods without losing speed.

It is all in the circulation!

Happily, you don’t need to buy the book his articles were in – he has put them online.  But his whole site is worth reading.  Just read the “way sails really work” articles first.

They are the first five here

4) The Tasar Sailing Manual – Frank Bethwaite

Online – link below

Frank has some impressive books out, but this was the first systematic collection of his explanations of the difference between just plonking around on the water and unleashing the potential in our boats.  If you are a high level sailor, you won’t need it.  but if you have sailed a bit and want to find out why some people seem to be able to get half a leg in front of you during a race – then this is the perfect resource.

For higher level sailors and those interested in more theory I recommend his “High Performance Sailing” and the follow up volume as well.

5/ Sail, Race and Win – Eric Twiname

Out of print – Amazon, second hand, libraries

The late Eric Twiname – a high level sailor from the UK – realised that he and his then girlfriend spent similar hours practicing the piano.  He regarded his standard as a “Good Pub Level” whereas his girlfriend was a concert level performer from a young age.


Ignore the Jingoistic title and read the book.  A lot of the problem is that we want to WIN too much!  This shows a different way.

This book has completely shaped my thinking about competitive racing and also how to LEARN from life in a general way.

It informs this article on my website – Low stress way of racing sailboats

6/ Start to Win – Eric Twiname

Out of print – Amazon, libraries, secondhand

This does for boat handling what his other book does for racing.  Twiname’s constant thesis is that ANYONE can bring themselves up to the level required to win a State or National championship.  Even if you don’t want to go that far, it shows how to think more dynamically about your sailing.

It is also an extremely useful book for boat design.  It identifies how a boat really behaves under pressure and how good sailing methods can either counter or redirect that pressure into useful behaviour.  But the descriptions of what happens when you do something in a boat will add hugely to your thinking about design.  As an example it allows you to start making real comparisons about the differences  hullshapes and configurations make to the way a boat handles – just because you know what to expect.

Suggestions:  If you have something that you think is brilliantly written, based on practice, rather than theory, enjoyable to read for everyone but eye opening – feel free to add a comment.

7 thoughts on “The Canon – Tools for thinking about sailing and boat design – Books and Articles

  1. How has your experience with the OzRacer/PDRacer affected what you want to do with subsequent boats? Specifically, from what I have seen of the change in size from the little 8′ boat up to the Goose size, it appears to be a solid performer. Maybe not the fastest but for a lack of a better description, downright mannerly.

    Even more so, how do you think that a properly scaled up (not just stretched) box boat up to the size range of the GIS would stack up, other than the obvious of not handling chop nearly as well as the GIS. Are we just holding on to the romantic notion of a pointy boat? I know that Oz had it’s share of scows. Why did they die off?

    • In a way the PDR/OzRacer line is not like other sailing scows. With regular sailing scows you can heel them to reduce wetted area in light winds and upwind. But the PDR, because of its sides being straight will dig in the corners of the bow and stern transoms if you heel too much.

      The scow Moths in Oz died off because they were outperformed by narrower skiff moths.

      The thing that the PDR points out to me most strongly is
      1/ That you can’t beat stability if you want to get performance out of a small package.

      2/ Aft rocker shape is what is responsible for the bows of sailboats raising out of the water at speed. Good when going downwind in waves. The PDR overdoes it a bit – but it does improve the safe handling of the boat. In my designs I’ve started putting just a shade more rocker in the backs of the boats if rough water handling is a priority. I think that is at least part of the reason multihulls tend to concentrate rocker in the backs of the boats – it means you can push the boat harder and faster without the nose going in.

      3/ A frivolous attitude to designing and building leads to many fruits!

      As far as expanding the length of box boats more and more …
      … in a way I don’t think it makes a lot of sense. There starts to be so much materials and effort put into a bigger boat that the pressure to build something nice looking starts to be strong too.


  2. Hi Micheal,
    I remember reading J. E. Gordon nearly twenty years ago and you’re right it is well written and easily read. I also thought that I could sail and from reading through some of the articles you’ve linked to I’ve been re-educated. Keep up the good work.

  3. Hi Michael,

    Thanks a lot, this was very interesting! I had been wondering why the dagger board and rudder of the oz racer were so “enormous”. I am dreaming of building a GIS, but have neither the time nor the building space at the moment. So I bought myself a very cheap O’Day daysailerII (17′). The rudder of the DSII is probably even a bit smaller than the oz pdr rudder. Now that you have cleared up this mystery for me, I’ll probably just go an build something similar to the oz racer rudder for my dsii (it has got only the original fibreglass “slabs” for centreboard and rudder, horrible).
    A great thanks for your beautiful designs and all the knowledge you are sharing so generously! As you mentioned above; the internet at its best.

    best regards,

  4. Gary Dierking of outrigger fame has a added a link to this article on his website.

    A nice page of outriggers too.

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