Hull form displacement motorcruiser

How does hull form make a difference in seaworthiness, rollstability,...in a displacement motorboat?
Hard-chine, multi-chine, round bilge, what is best for the open sea?
For instance, I have seen that most of the Bruce Roberts designed trawlers are hard-chine.

In Holland, most boaters are convinced that hard-chine is not suited for rougher waters, you need a multi-chine or a round bilge (round bilge is best, they say).
Are they correct?

Is there a big difference between a multi-chine and round bilge?
Would a multi-chine be the ideal compromise between the simplicity and lower cost of the hard-chine and the more costly, seaworthy round bilge?

Any help appreciated.

Thanks!

Luc N
Belgium

 

This is a matter of greatly varied personal preference, and since there is a virtually infinite variety of possible hull forms, lumping them into categories based on chine type alone tells you very little about how a particular boat performs. There are simply too many other factors to consider, to simplify the decision so readily.

 

Well said marshmat. I will only add that a nice single chine hull should in no way be categorically considered inferior to a round hull or a double chined one. In fact I see so little virtue in a doulble chined hull that I would not even consider one, mostly because of the extra cost of fabrication. But if someone wants one they should go right ahead.

 

I would echo that. Stability, sea keeping ability, how the boat rides, and whether it rolls a lot are partly a function of the shape of the hull (the transverse shape at mid section) but also determined by displacement, center of gravity, center of buoyancy, metacentric height, her length and shape of the buttocks, and so on. So to just say a round bilge rides better than a chined hull would not be right.