Kayak is a very narrow boat like the ones in the pictures.  It has a hollow bottom for us to place our feet, called the hull.  The correct position to sit in a kayak is upright with the legs extended to the front into the hollow hull.  It is propelled using a double-bladed paddle. A kayak floats just below the water surface.  So as it moves forward, the water is pushed aside.  It is said that the earliest people to use kayak were the Eskimos.

Kayak is usually made of plastic material, mainly from polyethylene.  Polyethylene is the most widely used plastic.  Its waxy characteristic and its toughness make it suitable to be used to make kayak.

Another similar vessel is the canoe.  It is slightly different from kayak as it floats on water surface and it uses a single blade paddle.  The sitting position in a canoe is also not the same as in a kayak.

Kayak is used as a recreational sports and at the same time it can be used in a race for those who are more competitive.