Review and comparison of The Aerohydrodynamics of Sailing and The Design of Sailing Yachts
Under construction, 15 July 05. I'll be right back.Are either of these books for you?
If you're looking for a book which tells you how to get the idea out of your head and onto paper, I recommend Kinney's ``Skeene's Elements of Yacht Design'' (8th edition) and Chappelle's ``Yacht Designing and Planning''. Both give enough advice about how to draw a boat that you can do it, and both give enough advice about what to draw that you should be able to avoid making an unusable, dangerous freak. You'll find my review of them on my Chappelle and Skeen page.
If you want to know the ``why'' behind the ``what to draw'', and if you don't mind a bit of elementary, applied math and physics, these books are what you're looking for.
The Common Topic
Aerohydrodynamics and Design are about applied aero and hydrodynamics. That's covered a bit in every undergraduate mechanical engineering curriculum, but these books cover the specifics of applying the science to sailing yachts. Fluid dynamics is a mathematical, computationally messy subject, and it's not amenable to a simple, nonmathematical treatment. You'll find that both books assume a certain familiarity with the basics of undergraduate math, statics and dynamics, but each, in it's own way, introduces the specifics you need, as needed. You don't have to be an engineer to read these (I think), but I'm sure that it helps.
These books give an overview of the fluid dynamics problems the yacht designer faces, and teach the basic principles of fluid dynamics and the specifics of how to apply them in yacht design. Even if you're a mechanical or aeronautical engineer, I think that the specifics these books present will be important, new information. If fluid mechanics is a new area for you (as it is for me), the material in these books is going to be vital.
The Books
Both Aerohydrodynamics and Design introduce the basic problems of yacht design: the forces of wind and waves which act on the boat.
Reviews
The Design of Sailing YachtsPierre GutelleWhere to find it:Not in the public domain.Buy it used at Amazon.com: Design of Sailing Yachts Table of Contents
ReviewThis is the poor man's Aerohydrodynamics of Sailing. It's the poor man's version because it costs (used; it's out of print) about ^{1}/_{3} what Marchaj's cannonical tome costs, and because it covers less material in less detail. That's unavoidable, since it has 208 pages, compared to 768 for Marchaj's 3^{rd} edition. That lack of bulk may not be as disasterous as it sounds: some of the extra bulk of Aerohydrodynamics of Sailing is pictures, case studies and opinion. Gutelle does cover much of the same material, and his work has the advantage of a simpler presentation. This book is written like an undergraduate text book, and is a bit less demanding of the reader than Marchaj's book. There is definitely more to recommend this book than low price and light weight. Gutelle has done a good job of covering the material and of getting it across, and the lack of breadth and detail enables him to give a slightly clearer, more straightforward exposition. 
The Aerohydrodynamics of SailingTony MarchajWhere to find it:Not in the public domain.Buy it at Amazon.com: Aerohydrodynamics of Sailing Table of Contents

Summary
Both of these books are moreorless mathematical treatments of applied aero and hydrodynamics. This is a very technical, rather demanding subject, and it requires one to be comfortable with thinking like an engineer. Both these books do a fair job of teaching the basics of fluid dynamics, and both do an excellent job of teaching how to deal with the special concerns of the naval architect.
If you must get only one ...
If you want to learn this subject in depth, href="http://www.amazon.com/exec/obidos/redirect?tag=booksandrev0820&path=tg/detail//1888671181/ref=pd_sim_books_2?v=glance&s=books">Aerohydrodynamics is probably the better choice, since it has far more detail, wider coverage, more references to the source materials, and more a magisterial approach.
If you want an introduction, but don't feel the need to become an expert, Design is probably the best choice. It's a bit cheaper, and a bit less demanding. You won't really miss what this book leaves out: you'll get the basics.
For self study ...
For selfstudy, it's probably worth while to get both of these. If you have trouble following Marchaj, you may find that Gutelle clears things up, or the other way around. Also, good as Marchaj's book is, it's good to have a second opinion.