Boat Construction - Why Sailboats Look As They Do

The purpose of this article is to give a cursory look atmaking is that, however the special purpose of a boat
boat construction, not so that you would be able toaffects the design, it will still be within broad controlling
build one, but to show some of the reasons whyfactors.
sailboats look as they do. Although there is a hugeMaterials used to make hulls
range of designs for boats they are basically theIn the same way that design can change for special
same whether they are a racing dinghy, a fishingpurposes, so has it changed in the last few decades,
smack, or an ocean racer or cruiser. They are as carsespecially because new materials have become
are -- the design changes only with the purpose of theavailable. In fact materials from which hulls are made
machine, and after that for cosmetic effect.have changed dramatically. Designers have moved
So boats, generally, are sharp at the end that goesfrom wood, fibreglass, aluminium and steel to specify
through the water first, they have varying degrees offoam and Kevlar sandwiches, end-grain balsa held by
width (beam) and they are blunt at the trailing end.thin wooden skins inside and out, carbon fibre and
They will have a mast, either tall or short, and they willother space-age materials. Also, instead of being
have sails. Because they have sails, they must have aconstructed in a style which had not changed much
keel. If the boat is a fishing smack it will be slow, it willsince Biblical times, hulls are now moulded, and are
have a short mast, and it will be made of enormouslyeven baked in giant ovens to cook the exotic materials
strong timbers because it has to survive heavyinto a lightweight shape that is lighter than alloy and
weather, it has to carry a heavy catch, and it has tostronger than steel.
have great power to drag its nets.Hull shapes
If the boat is a racing dinghy, it will hold two, sometimesHull shapes have changed, too. The fat, shallow,
three people. It will be light enough to carry to themodern boat sails to windward far better than the
beach and trail home, and it will have a dish-shapedtraditional styles by utilising lift from the keel. And,
bottom and a centreboard. This is because it usuallybecause they are light, the modern boats run far
sails in sheltered waters, the weight of the crew keepsfaster. The only advantage the older, heavier boat has
it upright, and it wants as little wetted surface asover the modern boat is that it is not thrown sideways
possible so that it can travel as fast as possible. Anas much in big, breaking seas.
ocean racer won't have a doghouse (the bit of theBut, however much shape and materials have altered,
cabin that sticks up above the deck), it will have athe skeleton of a boat is still much the same. To
mast that seems ridiculously light for such a powerfulunderstand the structure of a hull is to understand the
vessel and it will have a wide range of sails to choosestrain on it and to know when to take that strain off. It
from.is outside the scope of this article to discuss design in
The ocean cruiser will have a solid mast, often withthe sense of which is the latest or which is the best.
steps up the side. It will have a big cockpit, and a bigEvery boat buyer decides that personal equation
doghouse. The boat will tend to have more beam thanhimself. We only want to understand enough about
the racer, although not necessarily so, and it will haveboat construction to see how the design and building
sails that furl into the mast, or around themselves, withabsorb the stresses handed out by the sea.
the controls running back to the cockpit. The point I am