Three ways to model a chine hull

http://www.cadfamily.com/a/CAD_CAID/Marine/Three-ways-to-model-a-chine-hull_1631.html

There are three ways of producing surface discontinuities (or chines)
in a hull:
1) Compacted control points
Only a single surface, useful for blending a chine into a round bilge.
More complicated fairing, more difficult to adjust spline stiffness.
Non-optimum control point distribution for different areas of surface.

Perhaps the simplest way to make a chine hull is to make the
transverse flexibility of the surface linear (order 2). This will make
the surface piecewise linear, with straight lines joining the control
points. You can still maintain a smooth hull in the longitudinal
direction by using a flexibility of 3 or more in the longitudinal
direction.