Canoe

In its human-powered form, the canoe is ordinarily propelled by the use of paddles, with the number of paddlers depending on the size of the canoe. Paddlers face in the direction of travel, either seated on supports in the hull, or kneeling directly upon the hull.

Paddling can be contrasted with rowing, where the rowers face away from the direction of travel (though a wide canoe can be fitted with oarlocks and rowed). Paddles may be single-bladed or double-bladed.

Sailing canoes are propelled by means of a variety of sailing rigs. Common classes of modern sailing canoes include the 5m² and the International 10m² Sailing canoes. The latter is otherwise known as the International Canoe, and is one of the fastest and oldest competitively sailed boat classes in the western world. The log canoe of the Chesapeake Bay is in the modern sense not a canoe at all, though it evolved through the enlargement of dugout canoes.

The earliest canoes were made from natural materials:

Wood-and-canvas canoes are made by fastening an external waterproofed canvas shell to a wooden hull formed with white cedar planks and ribs. These canoes evolved directly from birch bark construction. The transition occurred in the 19th century, first, in Ontario, when canoe builders laid canvas instead of bark into a traditional building bed and, later, in Maine, when builders adapted English boat-building inverted-forms technology. In areas where birch bark either was scarce or where demand exceeded ready supply, other materials, such as canvas, had to be used as there had been success in patching birch bark canoes with canvas or cloth.

Aluminum canoes were first made by the Grumman company in 1944, when demand for airplanes for World War II began to drop off. Aluminum allowed a lighter and much stronger construction than contemporary wood technology.

Depending on the intended use of a canoe, the various kinds have different advantages. For example, a wood-and-canvas canoe is more fragile than an aluminum canoe, and thus less suitable for use in rough water; but it is much quieter — thus better for observing wildlife. However, canoes made of natural materials require regular maintenance without which they lack durability. A Kevlar canoe is tough and also light, good for wilderness tripping. Modern hybrids can combine the elegance and style of traditional wooden canoes with such benefits as modern materials can provide.

Many canoes are symmetrical about the centerline, meaning their shape can be mirrored along the center. When trimmed level (rarely the case) they should handle the same whether paddling forward or backward. Many modern designs are asymmetrical, usually having the widest beam slightly farther aft which improves efficiency and promotes more level fore and aft trim. A further improvement may be found in canoes with a straighter hull profile aft and rocker forward which improves tracking.

A traditionally shaped canoe, like a voyageur canoe, will have a tall rounded bow and stern. Although tall ends tend to catch the wind, they serve the purpose of shedding waves in rough whitewater or ocean travel.

Some canoes are made with squared sterns — "Y", "V", or "U" shaped — in order to permit the mounting of outboard motors. Very large freighter canoes can be powered with powerful motors, but canoes that are 18-feet-long or shorter would normally be propelled by motors of 3 horsepower or less. Side brackets can be mounted on canoes with pointed sterns to mount small outboard motors of about 1½-to-2 horsepower, which propel such canoes with surprising speed.

The shape of the hull's cross section significantly influences the canoe's stability under differing conditions. Flat-bottomed canoes generally have excellent initial stability, which diminishes rapidly with increased heel. Their high initial stability causes them to have a more abrupt motion in waves from the side.

For a given beam, a rounded-bottom canoe will have less initial stability than its flatter bottomed cousin. Round sections have lower surface area for a given volume and have less resistance through the water. They are most often associated with racing canoes.