The Kspline

The kspline is a new curve designed for parametric modelling of ship and yacht hulls. This powerful design tool is easy on computing resources, helping the designer concentrate on the design instead of the computer. It is available in the Friendship Framework, an advanced CAD/CAE application from Friendship Systems.

French naval architect Jérémie Raymond used the kspline to develop a new design system for planing sailboats. To my knowledge, this is the first systematic study of planing sailboat performance. Previous sailboat studies do not investigate planing, and powerboat studies are useless for yacht designers because powerboats do not heel and because their powerplants do not fluctuate.

Jérémie and I are developing a paper to be presented at the fourth High Performance Yacht Design Conference in Auckland in March, 2012.

I wrote about Jérémie's project in Ship and Boat International*. Click to read the article.

I described the technical details of the kspline in a paper presented to the third High-Performance Yacht Design Conference in Auckland in December 2008.

If you're interested in parametric hull design, email me at

* Reprinted with permission from Royal Institution of Naval Architects from Ship & Boat
International March/April 2010.

A parametric hull drawn with ksplines in the Friendship Framework.