How Cliff Diving Works

When you jump from a cliff, you go into free fall and gravity is the only force acting on your body. You encounter no resistance from friction with the ground as you would when running or skiing, and you suffer negligible air resistance. But gravity is a powerful force. As you fall, it pulls you toward the earth, or in the case of cliff diving, toward the water, at a speed of 32 feet per second per second (9.8 meters per second per second). Because time is a factor in this formula, the longer you fall through space, the faster you go. Free fall acceleration dictates that every second of your descent has an increased velocity over the second before it.

Higher cliffs don't accelerate your fall — acceleration is constant during free fall. The pull of gravity decreases infinitesimally at higher elevations, but it pulls you with an equal force from the first second of your jump until you decelerate when you hit the water.

What the height from which you jump affects is the speed with which you hit the water. If you jump from 10 feet (3 meters), you'll be traveling at 17 miles per hour (27 kilometers per hour) when you reach the water. If you increase your height to 50 feet (15 meters), you'll increase the speed of impact to 38 mph (61 kph). That's just the vertical velocity of your fall through space, the speed you gain from gravity acting alone — if you add some horizontal velocity, your impact speed increases. John G. Cramer, a physics professor at the University of Washington, explains that from the same height, "[A] diver who gets a running start and develops a significant forward velocity will hit the water with more net speed than a diver who dives straight down without a push off."

Then, when you hit the water, your velocity drops almost instantaneously. In about a second, you go from your maximum speed to zero [source: Castro].

Thanks to King Kahekili and his cliff-leaping warriors, many consider Hawaii the birthplace of cliff diving. In fact, for more than 40 years, the Sheraton Maui Resort and Spa has staged a nightly ceremonial re-enactment of Kahakili's spiritual leap. A loincloth-clad "warrior" carries a lei and torch to the crest of Pu'u Keka'a, a mountain Hawaiians believed dead souls leaped from to enter the spirit world. After offering the gifts to the sky in each direction, the warrior leaps from the cliff. But Pu'u Keka'a isn't the only place to leap — numerous other cliffs on the Big Island draw intrepid cliff divers who want to try it themselves.

In 1934, a 13-year-old boy, Enrique Apac Rios, leapt from La Quebrada in Acapulco, Mexico. From that jump grew an enduring tourist draw: La Quebrada cliff divers. Around sunset, this well-experienced team of professional divers starts showing off for visitors who flock to the cliffs to see the divers perform. As the sun slides away, La Quebrada Cliff Divers look down onto breaking surf from heights of up to 147 feet (45 meters) [source: Vacations Made Easy]. Timing the waves and focusing on the pinpoint of safety between the cliff and rocks, they hurl themselves from the cliff, tumbling and spiraling into the churning ocean below.

Dubrovnik, Croatia, on the Adriatic Sea has twice hosted events in the World Series Cliff Diving Competition — first in 2000 and again in 2009. Competitors faced their most arduous challenge here in 2009 when they had to complete eight consecutive dives from 85 feet (26 meters) [source: Welcome to Croatia].

Jamaica's long beaches, stunning sunsets and relaxed attitude create a vacation utopia, but the West End Cliffs in Negril is a hotspot for thrill seekers. The 40- to 70-foot (12-21 meter) limestone cliffs are popular with locals and tourists, who leap into calm, clear waters of coves and natural pools [source: Extreme Angles Publishing, Fearless Planet]. Hotels and restaurants provide platforms at differing heights — the highest platform at Rick's Cafe is 35 feet (11 meters) — for cliff-diving patrons.

Avegno, Switzerland is home to the World High Diving Federation, and the Cliffs of Brontallo host the WHDF Cliff Diving World Tour each July. Although spectators only have access to limited space, those who secure a spot are extremely close to the cliff-dodging acrobatics of the daring divers.

Cliff diving from any height can be unsafe — it's one of the most dangerous extreme sports. In fact, official tourism sites of popular cliff diving destinations don't promote the activity.

Cliff diving puts tremendous stresses on your body. If you jump from 20 feet (6 meters) above the water, you'll hit the water at 25 mph (40 kph) — the impact is strong enough to compress your spine, break bones or give you a concussion [source: Glen Canyon Natural History Association]. But that's only if you enter feet-first in a straight, vertical line — a horizontal, or "pancake," landing is like hitting concrete. Halving the height of the jump to 10 feet (3 meters) reduces your speed of impact to 17 mph (27 kph), and even cars sustain damage when hit at that speed.

Because of the high potential for injury, the World High Diving Federation recommends that no one dive from 20 meters (65.5 feet) or higher unless there are professional rescue scuba divers stationed in the water [source: World High Diving Federation]. Bruises, dislocated joints, broken bones, compressed spine, injured discs, and paralysis are among the injuries that cliff divers experience. Death is also a possibility.

Competitive cliff divers free fall from heights of 59 to 85 feet (18 to 26 meters), but professional show divers in Acapulco, the La Quebrada Cliff Divers, sometimes jump from 148 feet (45 meters) above the water [sources: World High Dive Federation, Red Bull Media Service, Vacations Made Easy]. These show divers survive to dive another day because of their years of training, familiarity with the area and their ability to adjust their dives according to fluctuating wave and water conditions. But even they occasionally sustain injuries.

The WHDF considers water depths of 43 to 49 feet (13 to 15 meters) adequate for dives from 65 feet (20 meters) or less, but water clarity is also a critical factor for cliff-diving safety. Hitting the water badly from a height can cause injury, but hitting something in the water — a rock, a branch, the bottom, even a fish — or the water body's floor can be fatal. Choppy waters and high waves often obscure the surface of the water and interfere with the precision of entry, but world champion cliff diver Orlando Duque says that waves break the surface of the water and soften the impact. Entering the water on the peak of a wave shortens the dive, and you must complete any acrobatics early in the dive so you can get your body into the proper position for water entry.

If you're overcome with the desire to experience the thrill of cliff diving, follow these tips to improve your chances of swimming out unharmed: