Happy New Year! This Year Reduce Nose Pokes and Pearls
Controlling Fluid Intake Brings a Safer New Year
Controlling Fluid Resistance Brings Safer Surfing
A nose poke or pearl dive is very dangerous. This usually occurs when a diving surfer impacts water with the front tip of his surfboard. A surfer is vulnerable to serious injury when he is catapulted down the face of a steep large wave, after his surfboard sticks or stops in water. In large surf, risks include long hold downs and drowning.
Surviving a big steep air drop clinging by your toes avoiding a nose poke, then shooting out of a deep pit with powerful spray at your back, is a joy of surfing. This and many other joys drive surfers to seek more thrills and bigger waves. These experiences shared with friends are life time memories. The worst memories are losing friends or any fellow surfer who share the passion, commitment and love for the sport.
Nose pokes have led to the deaths of two Hawaii Surfers, Mark Foo and Kirk Passemore. Although the pokes did not cause drowning or death, they led to dangerous fatal circumstances. The sad endings can bring life lessons to all fellow surfers. Analyzing what happens or what causes surfboard to stop in a pearl or poke lead to solutions that may reduce injury and death.
Let's dive into water from a low perch. We are cushioned by upward lift. As you penetrate water in a dive, your body pushes the water out of your path. Water pressure against your body is hydrodynamic force. Your energy is transferred to water in the form of waves. You generate waves, slowing and descending deeper until your energy or speed dissipates. Descent into liquid is only possible, if the medium has time to move out of your way. Should you fall into water from a ledge several hundred feet high, you will hit water carrying great speed. Water cannot move out of your way in time to allow penetration. You will momentarily stop on the surface, blocked by water until you decelerate. Water cannot absorb your impact, your body must take the crushing blow. Depending on how you land, you may sustain injuries.
High cliff divers usually attempt to land head first in water. Most of the impact is to the top of their heads. Their outstretched arms and hands part and break the water surface. The force is tremendous and impact intensity increases with height and speed. The diver head butts water and pushes it aside. He decelerates as he pushes water. Imagine hypothetically, what would happen if a diver held his head up protruding like an appendage, so he could see where he's going. He would hit water face first. Such a landing could cause black eyes, a bloody nose, concussion and and injury to his neck or spine. In a face plant landing, water cannot move out of an extended head's way, to cushion impact. The diver is moving too fast. Water can neither move nor compress, so a diver's face and neck absorbs impact.
A diving surfboard with high nose rocker has similar features to a diver with his head held up. The extended head is an appendage exposed to impact. High nose rocker bend is also an appendage. The underside of this appendage is flat in most surfboards. When a surfboard hits water on the flat underside, it generates resistance or lift. The surfboard may dive under water after losing speed. The initial impact on the flat nose underside stops the surfboard and pitches the rider. As the diver's flat face absorbed impact, the flat surfboard underside does the same. Water does not move, both diver and surfboard momentarily pause on the surface. They submerge after the appendage generates drag causing enough deceleration so water moves out of their path. Drag twists the diver's neck and abruptly pushes the surfboard backward. This drag is hydrodynamic resistance.
Surfers can recover from a shallow dive. Moderate rocker will keep a surfboard moving in a nose poke. If high rocker is preferred, the bow should not be flat. Flat bows push water forward before it moves aside, taking valuable time. Vee or round bow will push water aside, out of the rider's path to perpetuate momentum. Water cannot be penetrated by speeding flat objects. Speed generates resistance, requiring more time for water to move. A speeding flat bottom surfboard stops when water cannot move out of its path in the given time interval. This is the same force or lift that allows a surfer to plane on a wave. When the force is applied to the aft half of the surfboard, the surfer planes. When the force is abruptly applied to the forward half of a diving surfboard, the surfer is catapulted.
It is not possible to avoid a nose poke, eventually everyone does one. It is not possible to recover from all. The underside of a surfboard is usually flat end to end. Flatness in the nose underside or bow, does not work well when impacting water at high speeds or through chop. In such conditions, a round or vee bow will move water out of the surfers path, he may ride farther, possibly out of harms way. The following video of Greg Noll, on a round belly surfboard from our past, demonstrates this.