:
: http://www.boatdesign.net/forums/design-software/free-ship-2-6-vs-prediction-resistance-holtrop-mennen-started-method-15963-17.html#post359847

: It is a more recent version than I have so I haven't tried it. It
: should be OK as no later posts raised any problems with it. The
: older site has gone.

I think it might be best to stick with the last version of freeship - freeship 2.6. It is still available at:
http://sourceforge.net/projects/freeship/files/
download both the 2.6 file and the manual file for the language you wish.

After version 2.6, the program was separately developed in 2 separate paths:

- Delftship - a commercial version and a lesser functional free version by the original author. The free delftship version is not as capable as freeship 2.6 and not backwards compatible to freeship 2.6. However freeship 2.6 files (as part files) are upward compatible to delftship free - if you like some of the graphics of delftship free. (I don't know the interchangability of the commercial version). available at:
http://www.delftship.net/

- Freeship-plus 3.16 and counting - this an offshoot developed by another author who is building onto the original freeship 2.6, however the early versions of freeship-plus were not stable for me. I believe freeship 2.6 files are also upward compatible to freeship-plus 3.16 files and not vice versa, however I have not played around with the more recent versions. The most recent versions are available at:
http://www.freeship-plus.pisem.su/indexEN.html

I don't expect that freeship-plus files are interchangeable in any direction with delftship files. This just might be an expectation only - I can't remember whether I checked it out.

For the free approach, I would suggest doing and keeping all original work in freeship 2.6 and then just using that file incidentally for looking at the alternate program's capabilies such as graphics or stability etc.
But really the freeship program is so capable, that those of us who use it should probably spring for the reasonably priced delftship pro to give martjin - the original author - something for all his good work.