A Boat Before Sail
Before a boat can go anywhere, it has to perform the rather more urgent trick of not sinking.
A fallen trunk offers a place above the water, although it is inclined to roll and has nowhere convenient to put lunch. Hollow out the trunk and there is room to sit inside it. Lash several floating pieces together and the load can spread across a platform. Build a light framework and cover it with a watertight skin, and the shape need no longer follow the outside of one tree.
Each arrangement gives people somewhere to be carried. The main body doing that job is the hull. Remaining supported at the water’s surface is flotation. A hull may float perfectly well while going somewhere its occupants would rather avoid.
A body to carry us
The hollowed trunk is a dugout, also called a logboat. Its maker removes wood from the inside while leaving enough for a continuous outer body. A raft carries its load on connected floating elements, which need not enclose a hollow space. In a reed boat, bundles of reeds supply the material from which the body is assembled. A skin-on-frame hull separates two jobs: a framework holds the shape, and a covering stretched over it keeps the water out. The covering can be animal hide or another suitable material.
These answers call for different resources and skills. Hollowing a large trunk requires suitable timber and tools, while assembling bundles requires good binding. A covered framework makes joints and the fit of its covering important. Materials and workmanship determine which shapes are possible and how well they last. Different communities developed such craft in different circumstances; they do not form a single sequence through which every boat passed.
One particular dugout survives from around 8000 BCE. Found in peat near Pesse in the Netherlands, the Pesse logboat was hollowed from a pine trunk. It is evidence of a boat made in that place and period, rather than a date for the invention of boats.
A craft used on water can be called a vessel. Boat is the familiar name for many of the smaller examples, though there is no universal length at which every boat becomes a ship. Yacht describes a vessel associated with pleasure or sport, rather than one particular body shape. A sailing yacht is designed to be driven chiefly by sails: surfaces supported above the hull so that moving air can act on them. That label does not tell us how many hulls it has or precisely how the sails are arranged.
For now, take a small open boat without a sail. Give it a forward end, the bow, and a rear end, the stern. Those names belong to the boat even when it happens to travel backwards.
Directions that turn with the boat
Place one person near each end. The person near the bow is forward, or fore; the one near the stern is aft. Between them is the middle region, amidships. An imaginary centreline runs along the middle of the hull from bow to stern. Anything lying fore and aft follows that lengthwise direction.
Facing the bow, the boat’s left side is port and its right side is starboard. Turn to face the stern and your own left and right change places relative to the boat. Port and starboard stay where they were. A request to put a bag on the port side therefore works without first checking which way its carrier is looking.
The name starboard comes from the old English name for the steering side, where a steering oar, a long blade worked in the water to turn the hull, was used. Port eventually replaced the confusingly similar name larboard; the Royal Navy standardised port in 1844. The fixed pair is still useful on a boat whose steering equipment is elsewhere.
Ahead and astern can describe positions: a floating branch lies ahead of the bow, another astern of the stern. They can also describe movement. Push the boat backwards and it moves astern while its bow continues to point towards the branch ahead. The ends of the hull, its direction of travel and a person’s viewpoint are three different things.
A hand, a blade and a direction
Dip a hand in the water and push it backwards. The water pushes back on the hand, and through the person’s body that force reaches the boat.
A broad blade on a shaft gives the hand a larger working surface. Held freely by its user, this tool is a paddle. Working it through the water is paddling. A backwards stroke can drive the hull forwards relative to the surrounding water. Producing that useful driving force is propulsion.
Where the force acts matters too. Work a blade on one side of the boat and it can turn the hull as well as drive it. Change sides or change the stroke, and the turning effect changes. One paddle can supply propulsion and steering. A person can stop making strong propulsive strokes and still use the blade to correct the boat’s direction.
In shallow water, a pole, or punting pole, can reach the bottom. Pushing against the bottom moves the boat without a blade working through the water. The method depends on being able to reach a suitable bed. Farther from shore, the same length of pole may find nothing to push against.
A pull can arrive from elsewhere. A towline connects the boat to another vessel or a pull from the bank. It carries the pulling force; the effort comes from whatever is doing the towing. Such a line may be made from rope, a flexible length of fibres or wires twisted or braided together. Its flexibility lets it lead between moving objects while it carries a pull. How those strands are made and joined will matter when the boat acquires more work for them.
Paddling, poling and towing continue to suit different places. A paddle needs little fixed equipment. A pole makes useful contact with a shallow bottom. A towline lets a force outside the boat do the driving. Choosing between them is partly a choice about what the surroundings make available.
Give the oar somewhere to bear
Now place a longer shaft against a support at the side of the hull. The support takes some of the load while the shaft turns. Worked in this arrangement, the tool is an oar. Its broad working end is the oar blade; its long body is the loom, or shaft; the end held by the user is the handle, or grip.
The oar acts as a lever, turning about its support, the fulcrum or pivot. Pull the handle one way and the blade moves the other way around that support. The pivot moves with the boat while water moves around the working blade.
The fitting that supports an oar at the boat’s side is a rowlock (pronounced “rollock”), also called an oarlock. A common version has a fork for the oar and a stem that turns in a rowlock socket fitted to the gunwale, the reinforced upper edge of the hull’s side. As the rower pulls, contact between oar and fitting carries force into the socket and then into the hull. The fitting is a bearing: a contact arranged to carry load while allowing the intended movement. The shaft can swing through its stroke while the boat takes the load at a defined place.
An older arrangement uses a thole, or thole pin, a peg against which the shaft bears. A pair of pins can guide it between them; a single pin can work with a retaining loop. A ring made from rope is a grommet. In a suitable thole arrangement, that ring helps hold the oar to its support as the rower changes the direction of the stroke. The pin provides the bearing and the loop provides retention. They have related but distinct jobs.
Repeated rubbing would damage a bare wooden shaft. Oar leather is a protective wrapping where the oar meets its support, taking wear at that contact. An oar collar, or button, projects around the shaft to limit how far it can slide out through the rowlock. Wrapping protects the contact; a collar locates the oar along its length.
These are useful details on a rowing tender, a small service boat carrying people or supplies between a larger vessel and the shore. The service tells us why it exists. The oars, supports and hull tell us how this particular tender works. Modern tenders can still use wooden oars with protective leather and metal rowlocks, while other boats retain tholes or use different bearings. The arrangements coexist.
Leverage also depends on distances. In a lever, a given force acting farther from the pivot has more turning effect. For the same required turning effect, a longer distance can allow a smaller force, with a larger movement at that end. The proportions of an oar therefore affect both handle force and handle travel. A long blade-side portion does not automatically make the rower’s pull easier. The handle length, the distance to the blade’s water force and the movement required all matter.
Crews and sculling
Working supported oars to propel a boat is rowing. A thwart, a seat or member running across an open hull, can give the rower somewhere to sit and help tie the sides together. The handles need room to move, so adding rowing positions changes the space the hull must provide as well as the effort the crew can supply.
In sporting rowing, a rower with one oar is sweep rowing; that oar is a sweep oar. In broader boat usage, a sweep can also mean a long oar. A rower using a pair, one in each hand, is sculling. Here the word identifies the pair worked by one person.
There is another kind of sculling. One oar worked over the stern sweeps from side to side. The operator changes the blade’s inclination so that the force from each sweep can push the boat forwards. The repeated action can propel the boat without lifting the blade out for a separate return stroke. A description of a person sculling with one stern oar therefore means something different from a rowing crew carrying two oars per person.
A yuloh is a form of stern sculling oar associated with Chinese boats. It works on a support at the stern, with a shaped shaft and a restraining line at the end inside the boat. That line helps constrain the motion as the operator sweeps the handle; the blade changes inclination and develops propulsion on alternating sweeps. Shape, support and restraint work together.
A steering oar is used chiefly to turn the boat or hold its direction. Its position and the way it meets the water serve that job, even though a similar blade elsewhere supplies propulsion. An Egyptian model from the tomb of Meketre, made in the early second millennium BCE, shows sixteen kneeling paddlers and two larger steering blades at the stern. Its paddlers and larger steering blades divide the work between different positions aboard.
Repeating supported oars along a hull allows a larger rowing crew. A galley is a vessel whose propulsion relies substantially on banks of oars, often with sails as well. A much later fighting-galley model in the Royal Museums Greenwich collection shows rows of seats and raised supports with thole pins. The supported oars distinguish its arrangement from the hand-held paddles on the Egyptian model.
Energy and effort
Pulling the oar handle through its stroke does mechanical work: the force transfers energy through movement in its direction. The rower’s body supplies that energy, which the oar transfers to the moving boat and surrounding water. Merely holding a motionless handle does no mechanical work on it, however tiring the hold may feel.
Complete the same work in half the time and the rower must supply twice the average power, the rate of energy transfer. More power and more force are different claims, because the distance moved and the time taken matter too.
A lever exchanges force and movement. In an ideal lever without losses, reducing the required force means moving that end farther to perform the same work. Real bearings and moving water also dissipate energy. Improved leverage can make the stroke manageable.
Let the crew stop. The boat coasts and gradually slows as it gives energy to the water around it. A steering blade can still act while water flows past it, though its effect changes as that flow weakens. The hull continues to carry the people throughout. Flotation, propulsion and steering have separate requirements even when one boat combines them.
The next person to climb aboard will increase the load without adding a single stroke. Before recruiting the wind, we need to understand how the hull carries that extra person, and why it settles farther into the water to do so.