Good Looking Craft
Book Extract
There are rules for producing a good-looking craft which should seldom be broken:
1. With few exceptions the above-water lines of the hull should be curvaceous
If there must be a flat line, then at least make it short – and the lines at right angles should not be flat – so that there are no flat areas. There is a practical reason here: a curved plate has ‘shape strength’, whereas a flat one is easily deformed. To understand this, take hold of a piece of paper and wave it. It is flabby and weak. Now wrap it into a tube, and it instantly gains ‘shape strength’.
2. Curves should please the eye, and the eye is quickly bored
So lines should alter their curvature along their length. There are certain exceptions to this: a stem which is a straight line is acceptable, a transom seen from dead abeam or the outlines of the keel may be straight. But almost all other lines of a hull should be curvaceous.
3. The sheer, that is the sweep of the deck seen in elevation, should be a bold curve with plenty of shape
No portion of it should be straight, not even for a short length.
4. The stem and the stern should not rake at the same angle, nor have the same height
5. Lines which are in the same area of the structure above the sheer should have the same slope
So the aft face of the aft cockpit coaming should have the same rake as the aft edge of the cabin top, and aft side of the aft window. If this angle is almost upright, then the fore end of the deckhouse should be much more sloped because ‘the eye is easily bored’ and does not like forward and aft slopes to be identical or nearly so.
TYPICAL FEATURES OF A DEEP-SEA CRUISER
This lines plan shows typical features on a deep-sea cruiser. The slope down at the aft end of the keel helps to keep the yacht sailing straight in rough conditions, as does the long keel. This reduces the strain on the self-steering gear.
The aft cut-up reduces the area of boat in contact with the water – the wetted surface – and this enhances the light-weather performance. The cut-away aft also helps turning in confined harbours.