Kayak and Paddle Design

A kayak is a small human-powered boat that has a covered deck, and a cockpit covered by a spray skirt. Propelled by a double-bladed paddle, modern kayaks come in various designs and materials for specialized purposes. A kayak may accommodate one, two, or even three paddlers who sit facing forward in one or more cockpits below the deck of the boat. Kayaks are also called canoes in Great Britain and Ireland.

In general, a longer boat is speedier but a shorter boat may be turned more quickly. A longer hull has less drag, i.e. it can cut through the water with less resistance. Longer boats may also have a higher maximum hull speed, but increased friction offsets it to a large extent, and only becomes significant at racing speeds. Long-distance kayaks like touring and sea kayaks are themselves longer, the length ranging from 15 to 18 feet. Whitewater kayaks, dependent upon river current for their forward motion, are built rather short so that their maneuverability can be maximized. They are rarely longer than eight feet while some specialized boats such as play boats may be only six feet long. Recreational kayaks are usually 9 to 14 feet long.

A second design element is rocker or the curvature of the kayak from bow to stern. It also predicts the maneuverability of a kayak. A heavily "rockered" boat is capable of curving more than a boat with little or no rocker. So, the effective waterline of the curved boat is less than for a curveless kayak.

The designs of kayak hull can be classified into categories based on the shape from bow to stern and on the shape of the hull in cross-section. Among bow-to-stern shapes are symmetrical, fish form, and the Swede form.

Hull shapes are classified according to the roundness or flatness of the bottom, whether the bottom comes to a "V" at various points on the hull, and by the presence, absence, and severity of a chine, an angled join between two parts of the hull below the gunwales. The hull design contributes to the boat's primary and secondary stability. It also develops the resistance of the boat to tipping and sinking. Although a boat generally rocks from side-to-side, wider kayaks with more buoyancy away from the centerline will be more resistant to tipping and will have less chance to capsize than a narrow one with less buoyancy away from the centerline. Modern kayaks are mostly made from wood, fabrics over wooden or aluminum frames, plastic, fiberglass, kevlar, or carbon fiber. They are available in one, two, and sometimes three person models.

Kayak paddles are available in all shapes and sizes. Top-of-the-line paddles cost between $250 and $400, while standard versions can cost between $100 and $150. The most inexpensive paddles might cost $20 or $30. The cheaper varieties have an aluminum shaft and a plastic blade. Rarely do these maintenance-free models have a solid or stiff feel in the water.

A lightweight, yet stiff paddle is the key if you want to enjoy kayaking. A well-designed blade pulls and slices easily through the water. It feels like a natural extension of your upper body movements. Whitewater kayak paddles are normally about 180 cm long, and made of durable plastics and resins. As the blades are offset by 45 to 60 degrees, you will want a quick lesson in holding the paddle with the correct grip so the blades catch the water in the right manner.