To impress the judges, a dive must be spot-on from start to finish. Four-time Commonwealth gold medallist and BBC diving expert Chris Snode explains how it is done.

Divers mentally rehearse their dive in advance. They visualise themselves going through the movements and try to block out all distractions. It is called 'selective attention'.

The diver must be 100% focused when approaching the end of the board. Arms should be straight and swing through to generate power for the next stage of the dive.

The hurdle step generates height off the board, giving time to complete somersaults and twists. Arms swing directly above the head and the shoulders are upright to maintain balance.

For platform dives, the diver rocks up a few times to prepare. The arms are then circled as fast and close to the body as possible and the diver pushes off forcefully with the legs.

Handstand take-offs require great strength and balance. Divers must hold the position long enough to show they are in control (about five seconds) before springing off the hands.

In the straight position, the body must be completely straight and tense throughout. The feet are pointed and arms straight, either out in front or pointing towards the toes.

The tuck involves pulling the knees tightly into the chest, with the head between the knees. The hands should hold the shins just above the ankles. The rotation must be quick.

To pike, the diver bends at the waist. The arms are grasped tightly around the back of the legs, which must be straight and flat against the chest. The toes must be pointed.

In the twist position, the diver keeps the body taut and straight. The arms are pulled into position quickly and kept close to the body to maximise spin speed. Feet are pointed.

In synchronised diving, two team-mates execute their dives at the same time. They are judged on their technique and on how well they mirror each other's movements.

The divers' movements must be perfectly co-ordinated from take-off until they enter the water. They must travel the same height and distance. Poor synchronisation is penalised.

The key to a good dive is to enter the water vertically, with the body taut and aligned, feet together and toes pointed. On entry, the palms grab at the water to minimize the splash.

Divers are only judged on what they do above the water. The judges have a matter of seconds to give their verdict. They mark out of 10, making deductions for bad technique.