hooked on free hullform

I just found out about hullform, and what a cool program. Have alot of people designed IOM’s with this? Can anyone provide me with the idiots guide on how to us it better. How do I know how much draft? I know the rules give max so is ther any rul of thumb? How do you get more draft forward? Is there a way to figure out CE and CLR or is that just trial and error? If it is as simle as putting the measure ments John gave me in another thread then I will be building lots of new hulls. What is the max and min beam anyone has tried to build? How can you figure if the boat will float on water line? So many questions sorry.


All your questions are legitimate ones. Remember that the only dumb questions are the ones you did not ask.

It is possible that you are not fully conversant with the principals of naval architecture by virtue of the questions you have posted. No problem there. If you are to avoid a lot of failures or marginal results, with your boats, then some basics are well worth studying. I recommend a couple of books that are one of the keys to understanding what makes a boat tick. The Elements of Yacht Design; By Skene. Skenes is the old time bible of boat stuff. Another is The Nature of Boats: by Dave Gerr. Between these two you will get enough information to do good design work. Neither book is overly complicated and Gerrs’ is particularly easy to understand.

I know that nearly everyone would rather take the easy way out and let some magical computer program do the work. Me too! On the other hand if you know what the various parameters are, and understand the ramifications, then you can do a far better job with the program. After all, a computer program merely does what you tell it to do. No matter how clever the program, it is GIGO.

From a sociological point of view, one can rationalize studying a book on the premise that you are educating yourself. That often goes over better with a signifigant other than visibly messing with balsa, frp, or CA.

I mean no discredit whatsoever to you or other aspiring designers. I am acquainted with several model builders who waste a lot of time by building “wet dream” kinds of boats with no regard for the principals of physics. Such boats tend to perform below expectations. All because the ambitious builder did not do his or her homework. Life is too short to build clunky boats. I am espousing all this stuff with some real life credentials because I have spent waaaaay too much time building things that did not turn out so well. After a period of education my success/failure ratio became noticeably more favorable.

i have not used hullform myself. but i know a few people that have. and i have been told it is real good. it does everything a cad program will do
the person you might want to talk to it dan sherman. he plays with most design programs. i am old fashion. i find something that works for me and i sort of stick with it
but good luck
build a 3rater :zbeer:

In addition to collecting boats, motorcycles & ex-wives I am an avid book junkie. Messabout is spot on in recommending Dave Gerr’s absolutely fabulous “The Nature of Boats”. If nothing else it will ease your mind in knowing that you’re not alone in your “sickness”. It is a truly pleasing book to read & sure to find a place of honor in your nautical library. Skene’s text is from 1904 & is a bit dated but then again physics haven’t changed any in the past 100 years. It’s also a must have. Fortunately, there is a 2001 paperback reprint by Sheridan House & you should be able to find a copy (I got mine at Barnes & Noble Books). Another good reference is the 1936 “Yacht Designing & Planning” by Howard I. Chapelle. My copy is a 1964 reprint by W.W. Norton & Company. I’m not sure if there have been any subsequent reprints since then, so it might be a little tough to find. The real meat & potatoes text of nautical design books has got to be “Designing Power & Sail” by Arthur Edmunds published in 1998 by Bristol Fashion Publications. It’s a short, sweet & somewhat dry blow-by-blow guide to nautical design. It contains not only the design methodology but also the formulas that real naval architects use. You might walk a mile for a Camel but you’ll probably be willing to break an old lady’s arm for a copy of this book.

Happy yachting - Kip

Hi Andrew,

I have just sent you a private message.