"In suitable conditions some high performance boats can now sail around a course at an average speed faster than the wind."   - Bethwaite, 5, Introduction.

" In about 1960, the windward planing dinghy was developed." - Bethwaite, 5, Introduction. (enabled sailing upwind at more than wind speed)


1 Marchaj, C., Sailing Theory and Practice, 1985

2 Marchaj, C., Aero-hydrodynamics of Sailing, 1979

3 Marchaj, C., Sail Performance: Techniques to Maximize Sail Power, 2002

4 Fossati, F.,  Aero-Hydrodynamics and the Performance of Sailing Yachts, 2010

5 Bethwaite, F. - High Performance Sailing 1993

6 Vellinga, R. - Hydrofoils, Design, Build, Fly 2009

7 Wanberg, J. - Composite Materials, Fabrication Handbook #1 and #2, 2010

8 Larsson, Lars - Principles of Yacht Design 

9 Curran, Manfred - Aerodynamics of Sails, 1925

10 Nick Hayes - Saving Sailing 


Ketterman, Greg - Senior Project Report Trifoiler - discusses outward aiming hydrofoils

Ketterman, Greg - Sailing Anarchy forum on negative lift hydrofoils 

rghdc - Constructing curved hydrofoils

How a hydrofoil works, optimum angle of attack 

Sail force calculations - http://www.wb-sails.fi/news/SailPowerCalc/SailPowerCalc.htm

Calculating drag - Hull drag - 


Forums and Blogs


Boat Design http://www.boatdesign.net/forums/

Sailing Anarchy http://forums.sailinganarchy.com/

Sails http://www.blur.se/2012/01/03/michael-richelsen-the-science-of-sails/



Publications, magazines, blogs, etc.

Proper Course - blog

Sailing Anarchylivepage.apple.com


Yacht Pals 


Sailing Associations

North Jersey Yacht Racing Association - junior program contacts

Sails and Spars


Hall Spars



Quotes from Aero-Hydrodynamics and the Performance of Sailing Yachts by Fabio Fossati, Sailing Theory and Practice by C.A. Marchaj, Aero-Hydrodynamics of Sailing by C.A. Marchaj :


Sail Camber

Pg 132 - We can conclude... that sailing when well off wind a sail with a large camber is desirable.  This is particularly true true when sailing in fairly light winds.

Pg 133 - The desirable amount of camber on a sail for windward courses will therefore depend on the strength of the wind.... A sail should be selected which will not heel the boat more than 30º... when sailing close-hauled in light winds we require a maximum camber of /10...


Marchaj - Aero-hydrodynamics of Sailing


Heeling and Driving Forces from Sail

Pg 9 - In the close-hauled condition the driving force Fris roughly one-fourth to one third of the heeling force Fh.   

Pg 31 - Max heeling force for a Finn rig (76 lbs)


Thin vs thick wing sails

Pg 313 - thick wing sails are nothing as good as thin, soft sails in light weather conditions.


Aspect Ratio v. foil lift, Fs

Pg 42

Pg 40 - Lift and Drag of NACA 006 with aspect ratio of 6


Influence of drag angle on high speed performance, Hull resistance v. hull shape (skimming v. round bilge)

Pg 316- ….. the drag angle, eA, the most vital factor controlling the performance of any fast sailing craft…..

Pg 84 - Fig. 1.32 - compares planing hull to round hull


Streamlining hydrodynamic foils

Pg 324 - To conclude there is no point to using streamline but thin sections for rudders or fin keels


Sail area to dagger board area ratio

Pg 43 - foil area should be 4% of sail area, empirically determined


Speed Performance

Pg 86 - Tornado speed v true wind


Hydrofoil Sailboat Performance

Pg 108 - A lengthy paper by P. Crew (Ref. 1.40) gives valuable insight into some theoretical and practical problems concerninghydrofoil carft

Pg 109 - Comparison of performance of semi-planinghull with hydrofoil lifting boat - Fig 1.43

Pg 110 - There is nothing to be gained, in terms of speed, by the use of hydrofoils in combination with partially elevated craft...


Wing Sails

Pg 120 - the wing sail can hardly compete with soft sails at low wind speeds.....


Calculation of Total Aerodynamic Force of Sail

Pg 134 - FT = 0.00119*CT*SA*VA^2

Density of water

Pg 168 - The density of sea water is ... 835 times the density of air at sea level. - kinematic viscosity of air & of water, specific weight of salt water.


Finn Specifications and Performance of the Finn and other boats

Pg 52-3, 62-3


Drag of a Flat Plate

Pg 147 and 240

Pg 318 - flat plate lift dependence on Reynolds number.



Pg 227 - The resistance of drag consists of different components that are not easily separable but which interfere with one another.  They are difficult of handle on purely mathemetical grounds, therefore most of today’s knowledge is based pone experiments.


Skin Friction

Pg 287 - The skin friction drag of a yacht is a substantial part of total dr\ag, varying from about a third at high speeds to almos the whole at lowspeed.


Reynolds Number

Pg 256


Thick v Thin Foils

Pg 306 - Thck foils of greater camber can reach CL values around 1.8 and maintain hihg L/D ratio.  They are therefore superior relative to thin foils.  However their superiority if lost at low Reynolds numbers.(low wind velocities).


Lift Coefficient v Drag Coefficient

Pg. 389