The very useful and powerful free ship/boat design software, Free!Ship, has been growing up… renamed to DELFTShip, and now closed source, there is still a free version. Adding to that is a professional version that adds fairing capabilities, various input/output options (DXF and IGES) and other features. Still more extensions can be purchased to add capabilities high end users might need.
Not-withstanding arguments about open source vs. closed, this is still a powerful tool available for free for the amature boatbuilder.
There are forums available from the main web site, and a Yahoo group available for information and file sharing.