Approach: The forward steps taken by a diver toward the end of the 10m platform or 3m springboard. This precedes the hurdle and takeoff and usually involves three or more steps. 

Armstand: When the diver begins by executing a motionless handstand on the edge of the platform while upside-down

Back dive: When a diver takes off with his/her back to the water and rotates away from the platform or springboard

Balk: When a diver initiates motion to begin a dive but discontinues before leaving the diving board. A balk is declared by the referee and causes a deduction of two points per judge. If the diver balks again or falls into the water, the referee declares a failed dive. 

Degree of difficulty (DD): The numerical value assigned to a dive based on a formula that adds together the different components of a dive - approach, number of somersaults, number of twists, flight position, entry position, etc. The total score from the judges is multiplied by the degree of difficulty to determine the dive score. 

Entry: The point in a dive when the diver makes contact with the water. The entry can occur feet-first or head-first, with the ideal entry coming with the body in a vertical straight line. When entering head-first, the diver's arms should be stretched above the head, in-line with the body. In a feet-first entry, the arms should be straight and held to the diver's sides. 

Flying: Used to describe a dive in which the diver assumes a straight position from takeoff, or after one somersault in a dive such as 115C, before executing the remainder of the dive. The straight position must be held for at least one quarter of a somersault (90 degrees).  

Forward dive: When a diver takes off facing the water and rotates toward the water. The forward dive may start from a standing or run-up approach. 

Free position: A combination of straight, pike and/or tuck positions when a twist is also incorporated. It can be one position and a twist, or any combination of positions and a twist. 

Hurdle: Just after the approach, the diver hops, or springs, to the end of the board, taking off from one foot and landing on two feet. The takeoff occurs immediately after the hurdle. 

Inward dive: When a diver begins a dive with his/her back toward the water at the end of the board. Rotation on this dive occurs toward the board. Sometimes also referred to as a cut-away. 

Judge: Seven judges are standard in major competitions. Scoring is on a scale of 0-10, utilizing half-point or whole-point increments. In synchronized diving, there are 11 judges. 

Pike: A position in which a diver bends his/her body forward at the waist, keeping the legs straight and the toes pointed

Platform: A stationary, non-bending diving platform that is at least 20 feet long and 6 1/2 feet wide (in synchronized diving, a width of 10 feet is preferred). The platform height is 10 meters (or about 33 feet). The platform structure also includes levels at three, five, and seven and a half meters used for training. 

Referee: This individual, who is not a judge, is responsible for managing the competition and making sure all regulations are observed

Reverse dive: When a diver is facing forward and then rotates back toward the board. Also referred to as a "gainer." 

Shammy: The absorbing towel that divers use to dry themselves on the board before executing dives. Named for 1948 and 1952 Olympic platform champion Sammy Lee. 

Somersault: When a diver rotates around his/her horizontal axis in a circular manner. This can be performed in any of the six categories of dives (forward, backward, reverse, inwards, twisting or armstand). 

Springboard: An adjustable diving board that regulates "springiness," resting at three meters (about 10 feet) above the water. The springboard projects at least five feet beyond the edge of the pool. 

Straight: A position in which the competitor's body is straight and the knees and hips are never bent, with the feet together and toes pointed at entry

Takeoff: The departure of the diver from the board

Tower: The platform's entire structure

Tuck: A position in which a diver bends his/her knees, bringing the knees and thighs closer to the chest and heels toward the buttocks

Twisting dive: Any dive with a twist; a twisting dive can be a forward, back, reverse or inward dive