Yacht Design Office: the Design Process
In this article, we define a Design Process for yachts and other types of vessels based on our own experience, lessons learned gained in different pro…
Sail design – An overview
Having a good set of sails is crucial for enhancing a sailboat’s performance on the water. But what do we know about all the science behind sail des…
Structural considerations in sailboat design
All boats shall have adequate strength to keep the hull watertight and withstand hydrostatic and hydrodynamic loads without breaking. Besides these wa…
Considerations about the design of a sailboat
Although the borders of different hull concepts are not always clear, the main governing parameters when designing a sailboat in terms of performance are: Keelboats…
Performance aspects at different points of sailing
The forces and moments affecting a sailing boat vary a lot depending on points of sail, but also on wind strength and waves. The same…
The meaning of circulation
Circulation is one of the most misunderstood terms in sailing. Yet, circulation is essential to understand lift and why sails, wingsails, keels, rudde…
The Reynolds number
The Reynolds number is the ratio of inertia forces to viscous forces involved in the flow. Reynolds understood that while inertia forces were dominant…
Understanding the boundary layer
In 1904, Ludwig Prandtl introduced an approach to understanding and analyzing flows around bodies that produced a massive breakthrough: the boundary l…
Bernoulli’s principle
The physical significance of Bernoulli's equation is what is known as Bernoulli's principle. It states that when the velocity of a fluid increases, th…
Flows in sailing
Sailing boats interact with flows of two very different fluids: air and water. Moreover, sailing boats are able to make their way through the water su…
International Measurement System: Sails
The International Measurement System (IMS) is a set of rules that define what and how is measured on a boat. It is used by the Offshore Racing Congres…
Challenges in sailboat design
Using wind power and sails as the primary means of propulsion brings additional dimensions to the design of a sailboat compared to ship or powerboat d…
Added resistance in waves: “Pinkster” solver versus “Keuning 2006” comparison
In 1980, Johannes Albert Pinkster defended his doctoral thesis "Low frequency second order wave exciting forces on floating structures". His work focu…
Sea state and wave forecasting
The performance of a sailing boat is affected by the presence of surface waves. To understand how the waves influence the boat's performance, we need …
Wind-generated sea waves
Wind-generated waves occur when the wind blows over the surface of the sea. They are divided into gravity waves (wind sea, and swell) and capillary wa…
Hull appendages, planforms, and wing sections: what are they?
Fin keels and rudders have become the standard configuration nowadays for racing and cruising yachts and everything in between, be it inshore or offsh…
Wind triangle
The wind experienced by a fixed observer (true wind) is not the same wind an observer on a moving yacht will feel (apparent wind). The wind triangle h…
Points of sail
The points of sail refer to the course a boat is sailing in relation to the wind. They are defined in reference to the wind angle, which is the angle …
What the hydrodynamic resistance is and why it matters
The motion of a sailing yacht through water requires energy to overcome resistance. It is essential to know the mechanisms behind the generation of th…
The air-water interface
Water and air are two different fluids that enter into contact at the ocean's surface at what is called the air-water interface. This interface plays …