Standards for the water depth required for safe diving have been not been established with accuracy. Nevertheless, the height of the diving platform, the angle and technique of entry, and the weight and height of the diver, must be considered. The shape of the pool's bottom and the or visibility of water depth markings can also greatly impact the severity of a diving injury.
Pool Shape and Width
Most in-ground pools have a gradual slope to their bottom to allow for a deeper end for diving. In above-ground pools, there is often a deep area in the middle with grades going up the side. A frequent cause of injury is a collision with a steep grade (or "spinal wall") in such pools. If a diver hits the side of the pool, it may have been the pool width rather than the water depth that was the contributing factor.
Warnings and Visual Factors
Placing warnings around the pool may not be enough for the swimming pool's owner to escape liability entirely in the event of a diving accident. The water's optical properties naturally cause a diver to overestimate its depth. Cloudy water from lack of maintenance can magnify this effect. Poor lighting may be a contributing factor in the case of night pool diving or diminished lighting.