on October 14, 2009
Hydrofoils: Design, Build, Fly is an excellent resource for anyone interested in building a hydrofoil, learning about hydrofoils, or just dabbling in a new technology. You certainly won't be able to find another resource out there that contains such a wide range of information under one roof.
The information is presented at a level that will give you what you need without being overwhelming. I read the book without any prior knowledge of aerodynamics or hydrodynamics. Now I have a decent working knowledge of both, certainly at the depth necessary to start designing my own hydrofoil. The book is rich with information and filled with charts and graphs; I imagine it will work well for the novice, the experienced, and all levels in between.
The author's obvious passion for hydrofoils comes through loud and clear and is quite infectious. He writes with a wry sense of humor that entertains as it informs. All in all, it is a great "how to" book, a great reference, and a fun read.
on October 25, 2009
You don't have to love math to love Ray Vellinga's book Hydrofoils: Design, Build, Fly. You don't have to design a hydrofoil from scratch to get full use out of it (though terrific mathematical tools are here to help you do it). A hydrofoil in flight is a dynamic system in constant state of balance. If any parameter goes out of balance without being counteracted instantly, then your flight is over... sometimes precipitously over. Use this book to help you use the system, not be run over by it.
The book begins with history. Thomas Moy discovered the hydrofoil serendipitously in 1861 while trying to design airplane wings. Hydrofoils, it turns out, are not just the province of tinkerers, graduate students, and leather-faced sailors. Alexander Graham Bell, when he was not talking on the phone, built a really fast one. The world's navies built hydrofoil warships. As a former US Navy officer, Ray Vellinga recommends that the Navy abandon destroyers and cruisers altogether in favor of hydrofoils. His rationale: Less rust; more fun. It makes perfect sense to me, if not to shipbuilders or the Secretary of the Navy.
Ray eases you into hydrofoil design principles by starting with flight characteristics: stability, control, and trim; lift, area, and speed; drag and power; and ventilation, cavitation, and stalling. Especially helpful is Ray's careful grouping of interrelated characteristics so you begin to grasp how these conceptual characteristics will interoperate when the hydrofoil actually flies later in the book. You become comfortable with this. You get this stuff. Not only that, but the way Ray tells it, this stuff is funny.
With those natural characteristics established, the ensuing chapters illuminate the various design parameters, explaining how they work together or in opposition: weight and lift distribution; height and pitch; steering and roll; materials, stress calculations, and fabrication; selection of hull (and motor, if applicable), foil profile, plan-form, and aspect ratio.
The dynamic system of hydrofoils in flight sneaks up on you and comes together during the course of all this, whether or not you dive into the math. Ray puts it altogether on the printed page better and more palatably than I have ever seen it done. But that's as far as Ray can go until Hollywood buys the rights and makes the book into a movie. For now you must contemplate the text until the beautiful dynamic of hydrofoil flight comes alive in your mind. It will happen. It's like winding a watch and then watching the gears and springs come to life. You can do it. Start winding that watch now.
The world of hydrofoilers has been Balkanized since the glory days of hydrofoils faded in the 1960s. Hydrofoilers are isolated into special interest groups now with little interaction, first according to propulsion: motor, sail, or human power (or kites, or surf); then by use: military, commercial, or recreational; then by geography; then by geopolitics: (USA vs. USSR); then by area of interest: restorations, new designs, foil add-ons, water skis and wake boards, university projects, garage hobbies, or personal remembrances; then by size: static or radio-controlled scale model, 1-or 2-person runabout, pontoon houseboat, oceangoing yacht, major warship.
Hydrofoils: Design, Build, and Fly is common ground for all hydrofoilers in its compelling elucidation of the fundamentals all hydrofoils must obey, but differences are also satisfied here. Individual chapters are dedicated to individual interests: modeling, sailing, motor power, and human power.
Then you come to the final chapter on piloting and troubleshooting. The chapter begins, "If you think designing and building hydrofoils is fun you'll go nuts when you first fly one. They are exciting because they truly fly." Now there is your common ground. There is your motivation. Ray's book may just be the beginning of a New World Order for hydrofoils (though in a good way, without the black NATO helicopters circling ominously in the night). Hydrofoils rule, but they don't design, build, and fly themselves. If hydrofoils are to rise to their former glory, hydrofoilers around the world must find, embrace, and communicate their common ground. Hydrofoils: Design, Build, and Fly is a perfect and affordable start.
on November 5, 2009
Right from the preface your book touched a chord with me. I may have a technical background, but nothing satifies more than the practical challenge of building knowledge based on "doing". Here is a book that covers in detail all the ideas and data realted to my pet subject! Fortunately, in sailing you cannot predict all variables and and this goes even more for hydrofoil sailing which adds a further dimension. Having built and tested many configurations of sailing hydrofoil over the years I can attest to the accuracy and it is refreshing to have an accurate description of what is happening. Refreshing explanations of all those things you thought you understood but were not quite sure.
I have gleaned heaps of hydrofoil stuff, borrowed Grogono's book, Marchaj, [...], Tom Speer etc, but have never come across a condensed, comprehensive resource like this before... if only it were around 15 years ago when I first started mucking around with foils!! Simple tables, a ready reckoner, just what I missed in discussions with the theorists. Data consolidated, I even found some graphs I had invented for myself, which I now find were aparently already developed by others...
I am really impressed that magnificent design ideas such as Dynafoil and Moth get proper coverage. In Hyfibe I can see the embodiment of many best principles, it is now a real challenge to apply these to a sailing craft!.
This book is comprehensive and well presented and finally confirms so much of what I had gleaned over the years but had no speaking partner to check with. It also provides all the elements which I can readily develop into new designs. A fantastic resource of really neat ideas well worth testing. Totally recommended to anyone contemplating designing, building and flying with hydrofoils!
Dr. Ian Ward
on October 3, 2013
This book contains EVERYTHING you need to know (and there's a lot you didn't even know you need to know, trust me!) about hydrofoil design. All the physics, different designs, advantages and disadvantages of various setups are explained in a simple, concise, easy to read format. An added bonus is that the author, from his youtube video, seems like a really good guy; he's that quirky neighbor many people have that's a little bit of a smart ass, but knows everything, and always has tools to loan you.
I don't see any way to improve on the book; I wouldn't considering purchasing anything else on the subject, this has it all, and nothing more is needed.
on December 15, 2011
I was delighted to read Ray Vellinga's book on the subject of building-your-own hydrofoil boat. Replete with pictures, tables, and explanations, this well-organized publication takes you through all phases related to designing and producing a complete working product.
How does Ray manage to combine elements from some of the simpler concepts of lift to the more complex areas of fluid dynamics and stress calculations? With great clarity! His lifelong hydrofoil boat building experience, intuitive understanding of the subject, and gift for effective explanations gives him the ability to write a really complete book on the subject. In this single 250 page volume he covers a brief history of hydrofoils, their flight characteristics, their design parameters, and examples of many successful designs. If you want to know the yield strength of some key building materials or the roll stabilization characteristics of a dihedral shape, you can learn about them in this book.
Let me be clear . . . this work is an outstanding contribution to the subject.
Holland, a former Naval Officer, lifelong boat enthusiast, and forever student of Physics.
on January 1, 2015
Mr. Vellinga addresses many design issues, provides references and is very helpful.
He gives you the tools to get really close with your design, whatever it is. He covers from little to big, from pedal to sail to power. In doing so, he gets into many specifics of differing approaches to controls and stability. This book, combined with his youtube videos and hydrofoil websites you have many tools to accomplish building a functioning hydrofoil. I would guess its very difficult to produce a book that is all to everyone even on hydrofoils. He walks you through his proof-of-concept, pictured on the cover, which involves many complex and fundamental issues. If you want to build a hydrofoil, it would not be a mistake to read this book and keep it in your library. I "Spent" the $20 plus a little more and I'm glad I did.