open source yacht design soft

this should keep you busy:


System requirements:

* 1 GHz processor or faster
* Windows 95/98/2000/NT/XP
* Graphicscard with a resolution of at least 1024 x 768 pixels at high color (16 bit)
* Recommended memory of 512 Mb or more 

Open source and free!
Go and design some crazy stuff! No excuse anymore:devil3:

Thanks Wiz…

I’ve been using Hullform for the last year and having fun with it. This program looks like it could take me from Junior High to College! I’m sure it will be challenging to learn, but winter is almost here so I can’t sail anyway. Only trouble is, I seem to be spending the hours designing on the computer instead of building in the basement. I’ll sure be ready when we get serious about racing on the computer instead of at the pond!!!

I wonder if I’ll be able to convince Brett to try this one?

Bill H

I played with the program today. It’s fantastic for drawing hulls. More sophisticated than Hullform, and much easier to control more complex shapes. It has really nice graphics, too. I like that it can unfold chine designs into flat surfaces. I successfully imported a file from Hullform using offsets, although it was kind of a pain to set up the file.

That’s the good news. The bad news is that it doesn’t have the ability to heel the boat and recalculate centers, etc, that is a strength of Hullform. In fact, it’s hydrostatic calculations are minimal, and it won’t calculate drag on designs as small as our models. Can’t even verify the displacement with accuracy at our size.

I tried generating offsets from a new design to put back into Hullform, but I haven’t got it right yet.

If anyone else has figured out this stuff, I’d appreciate some advise.

If only the two programs could be put together…

sigh…Bill H

well it’s opensource and free…the guy is probably still working on it.
I guess in a few weeks? it will have more improvements…

I noticed there is a forum…maybe joining and asking questions:fish:

Free!ship Forum

[SIZE=-1][SIZE=4][SIZE=-1][SIZE=4][SIZE=-1][SIZE=-1] FREE!ship is a program developed to demonstrate the power of subdivision surfaces when applied to modelling ships. FREE!ship gives the designer more control and freedom in the design process compared to traditional NURB surfaces. Create any desired hull shape with only one surface.

FREE!ship is freeware and open source. The program as well as the full Delphi sourcecode is available from the download page or directly from At the moment FREE!ship is still under development. Check out the features page for more details.

I also remember that Maxsurf has an ACADEMIC version…2 layers but free…if you are a student…


Had a play as well,
very nice and easy to generate a hull shape.
Concur with Bill re hydrostatics in heeled condition etc.
I drew a 6metre hull so had no small size problems…displ seems to be in tons.
Will try drawing a model.
Upside is the nice graphics and the ability to add on a deck/keel etc.
I have been following this software the past few months and it is improving quickly with each version…I expect the end result will be very nice and will rival more expensive software.
The exporting functions are nice(DXF to AutoCAD) and the printed lines plan is in traditional format which I like.

Hey Wiz…since you got us working with FreeShip, can you allow .fbm files to be uploaded so we can share them here?

Thanks…Bill H

done :graduate:

files allowed as for now:


Wis -

thanks for your accomodations.

Any suggestions as to where to save? i.e. - include in a post within a topic - or - perhaps have one new section devoted to “plan files” only? Any questions or comments could be done in a thread post elsewhere, leaving only files in the “Plans” area. Just a suggestion before many too plans get “buried” in a topic thread.

Thanks much, Wis…Bill

just to keep this thread alive, here is a screen shot of a 3R design im working on using freeship. freeship has a slight learning curve, and one or two more features i would like to see (mainly smaller units). but it’s still as powerful as any other program on the market.

I finally got a new computer, that could handle programs like Free… and more importantly VirtualSkipper4, and I have been playing with FreeSip for couple of weeks, I’m still learning…….very slowly (have been also playing with VS…… a lot more).
I do have a question for you guys that are way more advanced than me, I know that you can not open hud files (Hullforms) with FreeShip, but is there a way to transfer the hull designs from one program (Hullforms) to the other (FreeShip)? It would help a lot, I would not have to start from scratch and speed up things a lot.

Thank you

Gio have you tried this? its in section 3.5.4 of the freeship userguide

3.5.4 Surface.
Import a textfile containing a number of 3D curves. This
option can best be used when the offsets of a round
bottomed hull need to be imported. These curves may
have any number of points which may differ from curve to
curve. Usually the curves run from the bottom of the hull
upwards, however longitudinal curves are allowed too,
just as long as all the curves have the same orientation
and run in the same direction. It is important that the
curves are not crossing each other.
The user will be prompted how many points in
longitudinal direction (number of columns) and in
vertical direction (number of rows) the imported
hull must have. Then the program fits a B-Spline
surface through these points such that the new
surface interpolates these points.
The first line of the file must either be a 0 (zero) or a 1. A zero indicates that all coordinates are in
meters while a one indicates that the coordinates are in feet. Each curve is defined by a sequence
of X,Y and Z coordinates separated by at least 1 space. The end of a curve is indicated by an
empty line after the last coordinate. The last line in the file should be ‘EOF’. The following is an
example of a file containing 3 stations.

A more extensive sample file can be found
in the FREE!ship \ships subdirectory and is
called Round hull import demo.txt. When
importing such a text file FREE!ship
assumes the following:
X-coordinates are longitudinal.
Positive Y coordinates correspond
with the portside of the ship. The base lies at z=0.0 and the aft perpendicular at x=0.0
All curves have multiplicity of 1. Having 2 curves at the same location leads to errors.
Whenever 2 curves exist at the same location these 2 curves must be combined into one by
connecting the two segments with a line lying on the center plane. These segments can later
be removed.
The curves must be sorted from aft to front (or bottom up in case of longitudinal curves), and
the coordinates of these curves must be sorted from the bottom to the top ( or aft to front in
case of longitudinal curves).’

Thank you for the suggestion Dan. I haven’t tried it yet, but I will during the week end (I’m at work right now…… ). Will let you know how (or if) it worked.


Would it too much to ask that somebody put up a file for a model boat? Any kind, too see how the program handles something that small…

what do you mean by ‘handles’? Your request is pretty vague.

Hey Dan -

before I spend a lot of time downloading, installing and trying to learn the program - can you - or other users - comment if the software provides a side view printout of the various lines created by the hull design - so they can be printed, transferred to MDF, cut out and glued up and eventually sanded/shaped to build an MDF plug?

Hullforms “looks” like it can do it, but I haven’t been successful in “slicing” the design in 1/4 or 1/2 inch thick sections. (no problems with bulkheads) Wondering if this product has that capability?


you can output as many buttocks, waterlines, and stations you want to dxf format.

I have personally used both hullform and freeship, and i learned freeship faster. currently freeship can’t do heeled hydrostatics, but they are in the works.

I mean that most of the designs are in feet (or tens of feet), rather than inches, so initially, the design has a fairly decent size on the screen. If the design was in so many inches (like a Footy) it might be so small on the screen that you couldn’t see it- per se. maybe it’ll automatically resize the image to be big enough to work with, or is that up to the designer, or the person viewing the design?

I’ll try to give freeship another go. It’s not easy to do with a touchpad.


the zoom functunality works great. :banghead:

I ask Dan ,why are you beating your head against the wall?
He said because it fells so good when I stop!