Cliff jumping is the leaping off a cliff edge, usually into a body of water, as a form of sport. It may be done as part of the sport of coastal exploration[1] or as a standalone activity. Particular variations on cliff jumping may specify the angle of entry into the water or the inclusion or exclusion of human-made platforms or other equipment. Cliff diving and its close relative tombstoning are specific to water landing (with diving usually implying a head-first entry and tombstoning implying a feet-first entry).[2] Cliff jumping with the use of a parachute would typically be classified as a form of BASE jumping.[3]
Cliff jumping has inherent dangers due to the high velocity that can be attained during a long fall. Multiple cliff-jumping fatalities are reported every year.
In 2015 a world record for cliff jumping was set by Laso Schaller, with a jump of 58.8 m (193 ft).[4]
Tombstoning is a form of cliff jumping popular in the United Kingdom characterized by upright vertical position of the body as it enters the water,[2] and the activity's name derives from a similarity between this posture and the form of a tombstone.[5]
At alternative to a cliff as a launch point is a human-made platform. Jumping platforms may purpose built or improvised, but they may also be repurposed existing infrastructure such as a railway bridges.
In the UK between 2004 and 2008, tombstoning lead to 139 incidents in which a rescue or emergency response was required. Spinal injuries occurred with 20% of these, and 12 people died.[6]
In recent years, injuries and deaths related to cliff jumping has increased calls for responses from local authorities and emergency services. A reaction to serious injuries and deaths at one popular tombstoning site, Plymouth Hoe, has led to the dismantling of seafront diving boards and closure of parts of the waterfront to discourage the activity.[7][8]
Water resistance increase with the speed of entry, so a high-velocity dive induces rapid and potentially dangerous decelleration.[9] Jumping from a height of 20 feet (6.1 m) results in a person hitting the water at 25 mph (40 km/h), an impact strong enough to potentially result in temporary paralysis of the diaphragm,[9] a compressed spine, broken bones, or concussion.[10] Horizontal velocity attained from a running jump may also add to the impact speed.[11]
| Fall height | Velocity reached at water surface |
|---|---|
| 5 feet (1.5 m) | 12 mph (19 km/h)[9] |
| 10 feet (3.0 m) | 17 mph (27 km/h)[11] |
| 20 feet (6.1 m) | 25 mph (40 km/h)[10] |
| 50 feet (15 m) | 38 mph (61 km/h)[11] |
| 85 feet (26 m) | 53–62 mph (85–100 km/h)[11] |
A phenomenon known as cold water shock and can disrupt the abilities of divers who enter very cold water[12]
Submerged objects also pose a direct risk to jumpers, who may sustain severe physical trauma upon colliding with them, or risk becoming entangled and unable to surface.[12] A too-shallow lakebed or seabed can also cause impact injury. In ocean conditions, tides can greatly affect water depth.[12]
As with any other water-based activity, strong currents can make timely exit from the water impossible.[6][13]
