K

kapok

The silky down from the seeds of the silk-cotton tree used as a stuffing for life jackets.

kayak

A canoe of Eskimo design with a light frame and a watertight covering except for one or two openings in the top for kayakers to sit in. A kayak is propelled using a double-bladed paddle.

kelp

Any of the 30 genera of large seaweeds belonging to the algae family.

kelp surface dive

Another name for the feet-first surface dive.

kick

Any of the various leg actions swimmers use to move through the water or support themselves at the surface. Common kicks include flutter, dolphin, whip, scissors, and eggbeater.

kickboard

A rectangular, foam flotation device with rounded edges at one end used to support a swimmer’s arms and upper body while practicing leg kicks. Kickboards are held out in front of the swimmer to practice kicking in prone position, over the swimmer’s head or against the chest to practice kicking in supine position, or between the legs to practice arm stroking.

kinesthetic awareness

The innate awareness of one’s body position and movement at any given moment during an entry into the water or the performance of an exercise or swimming stroke.

L

lactic acid

An intermediate byproduct of carbohydrate metabolism in muscles due to short-term, high-intensity exercise and other conditions of oxygen deprivation (e.g., shock, lung disease, heart failure, etc.). As lactic acid builds up, it prevents muscles from contracting. In an exercise situation, the only way to improve swimming speed is to adapt to and overload the metabolic and physiological systems involved.

ladder

A framework for climbing up and down that consists of two parallel sidepieces connected by a series of rungs used to step on which ascending or descending. Ladders for diving boards/towers and into swimming pools often have railings for extra safety.

ladders

A set of swims that increase or decrease in distance by a standard amount (e.g., a swim of 25 yards, 50 yards, 75 yards, and 100 yards).

lanyard

A short cord used to secure the rigging on a boat or to hold a whistle, keys, etc.

lateral

Toward the side.

law of acceleration

Newton’s second law of motion: Acceleration is produced when a force acts on a mass. The greater the mass of the object being accelerated, the greater the force needed to accelerate the object.

law of action and reaction

Newton’s third law of motion: For every action, there is an equal and opposite reaction.

law of inertia

Newton’s first law of motion: An object at rest will remain at rest unless acted upon by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

leading arm

When arms work in opposition, the arm reaching out in front of the body. In the sidestroke, the leading arm is also called the bottom arm.

lead poisoning

A severe reaction to swallowing lead or breathing in lead dust. Although gasoline and paint in the Untied States no longer contain lead, lead is still present everywhere, including in dirt, dust, old house paint, old plumbing and solder, etc. Signs and symptoms of lead poisoning include abdominal pain, vomiting, headaches, loss of appetite, changes in levels of consciousness, seizures, and coma.

Learn-to-Swim

The progressive swimming and water safety program of the American National Red Cross, consisting of 6 levels that teach people of all ages and abilities how to swim skillfully and safely.

leeward

The direction toward which the wind is blowing.

lever

A mechanism consisting of a pivot point and one or two rigid parts called arms used to apply force efficiently to lift or move an object.

lifeguard

A professional rescuer and first responder specifically trained to supervise the public in various aquatic environments, to make swimming rescues, and to provide first aid care as needed.

lifeguard team

A group of two or more lifeguards who work and train together so they are prepared to support each other in a crisis.

life jacket

Any of the various wearable personal flotation devices worn in and around the water and especially while boating, participating in water sports, and hunting or fishing. In the United States, all life jackets are tested, approved, and classified by the U.S. Coast Guard.

lifeline

A buoyed line extending across the width of a swimming pool at the breakpoint between deep and shallow water, at the outer edge of a diving area, or along the perimeter of an open water swimming area.

life preserver

A device (such as a life jacket or ring buoy) designed to save a person from drowning by providing buoyancy in the water.

lifesaver

A general designation for someone who watches over an aquatic environment and makes rescues within the scope of his or her training. In certain contexts and jurisdictions, the terms lifesaver and lifeguard are used synonymously.

life vest

Another name for life jacket.

lift

The principle that as fluid moves around an object, the individual molecules that make up the fluid speed up or slow down to stay parallel with the molecules on the other side of the object. This difference in speed creates drag on one side (where molecules are slowing down) and lift on the other side perpendicular to the direction of drag.

ligament

A tough cord of tissue that connects cartilage or bone to bone.

lightning

An abrupt electrical discharge in the atmosphere that produces a flash of light and a booming sound of thunder (due to the rapid expansion of air). Lightning travels at a speed of about 140,000 miles per hour (220,000 km/h) and reaches temperatures of up to 54,000 °F (30,000 °C).

liquid soap

A cleansing agent in liquid form, usually dispensed by a pump. Liquid soap dispensers should be available in the locker rooms at public swimming pools so swimmers can properly shower before entering the pool and wash hands after using the rest room.

littoral current

An ocean current that moves parallel to shore driven by the direction of the wind and waves. Also called a longshore current.

LKP

Last known position.

locker room

The men’s or women’s changing room at a swimming pool or gymnasium.

locomotion

The power or ability to move from place to place, either on land or in the water.

long bones

Hard, dense bones that provide strength, structure, and mobility. Long bones consist of a shaft and two ends and contain yellow and red bone marrow.

lumbar

The region of the lower back.

Lyme disease

A bacterial infection spread through the bite of the blacklegged tick.