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## The Quest for Lost Knowledge

Analysis

Problem:   Surfboards may abruptly stop at high speed when impacting water.

Hypothesis:

At high speed, hydrodynamic resistance pushes against the surfboard's flat underside at the nose rocker bend, stopping movement.

Research Subjects (follow): Physics, Wave Making Resistance, Cohesion and Adhesion, Nose Rocker, Gravity Force, Bow, Marine Technology, Movement Phases, Kinetic Energy, Hulls.

Soluion?: Semi-Displacement Hulls with Vee or round bows and moderate nose rocker can push water aside minimizing deceleration.  The board can transition to planning by deflecting hydrodynamic lift away from the nose.

Research

Physics

Physics is the study of matter moving through space and time.  Movement through space generates waves.  Every action or motion generates waves.  We constantly generate waves in our daily activities.  Examples are air waves, produced when we move and sound waves generated by speaking or yelling.  When a surfer rides a wave, he simultaneously creates waves as he move through water.

Physics defines a wave as an oscillation moving through a medium, which transfers energy.  The surfer’s medium is water, he transfers energy to water by displacing it.

Wave Making Resistance

Everything moving through water generates waves.  A splash is a wave and a wave is also called a wake.  Wake production can slow and stop a surfer.  A bow wave which forms under a slow moving surfboard, is water the surfer moves with his energy.   Energy transferred to water must be replenished continuously, or the ride will end.  The main source of energy for a surfer is gravity, which supplies kinetic energy.  When a surfer does not have enough kinetic energy to displace water out of his path, the ride ends.  An example of this is a pearl.  In a pearl dive, the nose of the surfboard submerges under water, and the surfboard stops.  A surfboards stops in a pearl for several reasons.  One reason is the surfer burns up his kinetic energy and has no means to acquire more.  Another reason is it creates drag in the form of a bow wave, even under water in a deep pearl dive.

Water sticks to objects, this is adhesion. Water sticks to surfboards, creating a water layer that moves with a surfboard.  This water layer moves independent of surrounding molecules, creating turbulence, which is drag.  A surfboard pushes water at lower speeds producing adhesive surface resistance and a bow wave.

Water sticks to itself, forming puddles, lakes, seas and oceans. This is known as cohesion.  Hydrogen's inter molecular bond holds water molecules together, making water viscous and resistant.  Water resistance prevents a surfer from bouncing off the bottom, in a wipe out.  When a surfer falls in water, he generates many little waves which radiate from his body.  The falling surfer displaces water in wavelets as he sinks.  A surfboard displaces water to move.  At high speed water cannot be displaced fast enough and blocking speeding fast objects.  Hydrodynamic resistance or lift is created.

According to renown chemist Barrett Stoller, the inter molecular Hydrogen bond is very strong.  The bond is even stronger in cold temperatures, which may affect surfboard performance.  The Hydrogen bond resists parting by flat speeding objects.  There is very little space between water molecules, therefore; water will not compress.  It actually pushes back when objects his its surface at high speed.  On the other hand, you can part water by slowly moving your finger through it.

## When someone falls in water, they displace water by pushing it aside.  As the person sinks, water moves out of his path.  Sink rate or descent speed gradually decreases to zero.  Water displacement cushions the fall.  Water is displaced and not really compressed. in a fall with lower impact and lower descent speed, water is displaced by the gravitational  force of the person's weight.

Falls from heights above two thousand feet into water, are usually fatal.  At these heights objects attain terminal velocity, which is the maximum speed reached by falling objects.  Due to velocity of the object, water cannot move out the way fast enough.  Very little water is displaced by fast moving, objects.  This causes a very hard landing.

Water Cohesion Can Increase Paddling Speed

When a surfer strokes hard, he creates a wave, with his hand and arm. This is again Wave Making Resistance. This resistance propels him forward. If he opens his fingers, he creates a larger wave, increasing resistance. Open fingers grab more water due to cohesion. Water molecules stick together to form a larger wave. This will increase thrust and add power to his stroke. When open fingers move rapidly, their wakes overlap and form a single large wake. The finger gaps are filled by the wake. When his hand moves slowly, the fingers instead, part water individually. With a slow stroke, water slips through his fingers. Higher hand speed with fingers opened generates greater resistance. This is a technique used by many Olympic swimmers.

The Foam Ball/Water Parts Water

Waves get their form, shape and size due to water cohesion. When a wave breaks, the lip impacts the base of the wave and breaks water cohesion. This creates two wakes or splashes. One wake shoots water and spray upwards in front of the wave. Another wake shoots water into the wave or barrel. The water shot into the wave, rolls in the curl. Due to the sticky properties of water, it develops into a foamy ball. This ball is called a foam ball. The foam ball can be blown out a hollow wave, with compressed air. A blast of air shoots out of the wave, when the cavern collapses.

Pic 21

Nose Rocker

A surfboard has rocker or nose lift, to prevent the board from penetrating the surface and submerging.  Rocker has diminishing returns, too much can slow the surfboard, and too little will cause it to go underwater.  Rocker forms a bow or bend on the underside of the board.  When this bend is extreme, and the bottom is flat the bow is exposed to contact with irregular water surfaces.  At high speeds, it is vulnerable an abrupt impact, which can launch a rider. Speed is the variable factor.  At lower speeds, moderate rocker on a surfboard with a flat bow, displaces water and surfboards continue to move.    When acceleration and deceleration is gradual a flat bottom works well, absorbing impact and displacing water.  The flat bottom cannot function well at high speeds in uneven water surfaces.

A misconception of modern surfboard design is, increasing rocker prevents pearling and stopping.  The premise is, a surfboard stops in a pearl because it cannot move underwater.  This is only partially true.  When the nose goes under water, pressure on the top of the board comes from the surfer’s weight and gravity forces, not water. Water shoots over the top of the board in rolling eddies. Shooting water does not stop movement in submerging. Surfboards stop in a poke or pearl because the bow pushes water.  A flat bow pushes water forward, before it is directed around the board.  At high speeds, water immediately accumulates ahead of the board, creating a wake that blocks movement.  The board abruptly stops and the rider is catapulted.  The flat board exhausts kinetic energy.

When rocker is increased by designers, it increases the protruding bend in the bow.  The bow normally pushes water out of the rider's path on contact, so the board can move forward.  The amount of water that must be displaced increases with speed.   At higher speeds a flat bow pushes water forward, building a bow wave.  Water needs time to flow and move.  A fast moving object will not allow time for water to move.  It blocks the surfboard.  Water is cohesive, molecules bond together and block a speeding surfboard.  This is hydrodynamic lift .  When lift is applied to the bent nose rocker underside it can push a surfboard backwards.  Water is unlike snow which can be pushed aside by the bend in a snowboard.

Alternatively, water can be directed under the board with concaves or around the board with a Vee or round displacement bow.  Concaves need to be deep enough to allow fast passage of water.   The nose may not have enough depth to allow rapid water passage.   Concaves in the tail direct water in the trailing wake and has little affect on the bow wave.  In order to recover from a shallow dive, the board must keep moving.  A displacement shape uses kinetic energy to push water out of a surfboard's path.  This permits a surfboard to move through water and recover from a shallow pearl dive or nose poke.

Gravity Force

Surfing is a gravity sport similar to skate boarding, skiing and snowboarding.  Surfing differs in that the mountain changes and moves.  Wave motion adds movement and danger to surfing.  A fast moving breaking wave affects a surfer by either giving him a boost or a terrible beating.  Ideally a surfer prefers to ride within the breaking wave using gravity to propel him.  Kinetic energy is generated by gravity forces on the surfer's weight.  Gravity is a surfer’s primary source of energy.

Surfers must balance the forces of gravity.  For this discussion gravity is simplified, not without recognizing a surfer's dedicated discipline of balancing and controlling gravity forces.  The center of gravity (CG) is a theoretical point on a surfboard where it is balanced on both horizontal and vertical planes.  The further forward of center a surfer moves on a board, the more it dives and gains speed.  The further aft of center a surfer rides, the more it noses up and stalls.  Weight left of CG produces a left turn and weight to the right generates a right turn.  Bottom turns and cut backs by skilled surfers are accomplished with a combination of aft and complex horizontal weight shifts.  A surfer's timing and rhythm keep him in sync with the wave.  Modern surfing with aerials, include turns in the air.  Surfer accomplish all by balancing the forces of gravity.

A nose poke occurs when the front end of the surfboard sticks in the surface of the wave.  The surfboard is usually nose down, relative to the center of gravity, and diving.  Gravity forces on the surfer’s weight drive the surfboard downward nose first.  Speed and weight are factors which drive a board in a nose poke.

When the board stops in a nose poke, it is due to resistance or friction under the board.  A long held belief, is that water slows the submerged board and causes it to stop.  This is only part of the explanation.  Deceleration is caused by a bow wave.  The bow wave is created by nose rocker bow driven by gravity forces on the surfer.

Below, a bow wave  sprays water over the nose of the board and against Kanoa's forward leg. Water shooting over the top of the board does not create drag.  Water shoots over the board in an eddy, even when the board goes under water.  Downward force is generated by the surfer's weight, not water.

Three vectors in the photo above depict the gravitational forces at work.  The vectors depict a typical inclined plane, physics analysis.  The left vector is perpendicular to the board, known as the normal vector.  The right is perpendicular to the horizon, and bottom vector is parallel to the surfboard plane.  The right vector is the weight vector,  its force increases with steepness.  The force in the bottom parallel vector represents net force or acceleration.  This value equates to motion when resistance or friction is low.  In this ride, the bow is efficiently moving water around board, reducing resistance.

Gravitational forces can be calculated with geometry and trigonometry.  Weight and mass are a function of gravitational force.  It  is not necessary to do the calculation in this case.  The surfer's weight is a factor driving gravitational force in a nose poke.  The gravitational force creates the bow wave which causes deceleration, by resistance and friction. The belief that water over a submerged nose causes drag in a nose poke, is a misconception.  Water over the top  effects only a very deep pearl.  The misconception resulted in higher and higher nose rocker, which creates more bow resistance or friction.

Bow

The flat bottom surfboard combined with its nose rocker forms a bow under the nose.   This is similar to the bow of a flat bottom boat. The bow of a surfboard, is usually out of the water when it is planning.   When a surfboard hits chop or the face of a steep wave, it contacts water with its bow. The bow leads the board and pushes water out of its way.  This is the surface where a bow wave is created.  The bow wave is usually not visible, because it is produced under the surfboard.   This is also the area where the surfboard pushes water when a surfer is paddling.

The following pictures are of an automobile wind tunnel test.  The angle of the stream would be equal to a surfboard's encounter with light chop.  In larger chop, the stream would approach from a higher angle.  Note the disruption in the air flow.  The change in flow is similar to the gap created when the air stream is deflected off the car windshield and roof.  Ideally. the laminar smoke flow should remain attached to the object.  All flat bottom surfboards would have a similar result.

Pic 14

Pic 14a

Marine Technology

In boat design, the flat bottom boat is best suited for flat or smooth conditions.  The flat bottom planes on the surface, performing at an optimum in flat water.  In choppy and rough conditions the flat bottom boat, bounces and produces an unstable ride.  A flat bottom boat can operate only at very slow speeds in rough conditions.    The flatness impacts chop, while Round or V-Hulls penetrates chop. The flat bottom sustains more pounding and slamming than other bottoms.  A Vee or Round Hull, is preferred for rough and choppy water, disbursing a bump rather than colliding into it.

Flat bottom boats efficiently minimize energy consumption.  In calm water, they ride on the surface.  The Flat bottom however, also attempts to ride on the surface in choppy conditions.  When moving against heavy seas, the flat hull can lose forward momentum.  This makes ocean crossing very difficult.  To keep moving more energy or power is needed.  More time is consumed in completing a journey.  The flat bottom boat is not efficient in rough water.   This is ancient knowledge.  The Polynesians, Vikings and Columbus crossed oceans in round or Vee hulled vessels.  They did not use flat hulls for ocean crossings.

Vid 10 features basic boat hull designs. It demonstrates how hulls function  in different conditions.

vid 10

A flat bow pushes a wake directly ahead of a vessel.  A round or Vee bow parts water and pushes it out of the vessel's path.

The boating principle of flat bottom for smooth conditions may apply to surfboards. In good clean conditions, the flat bottom performs well. Similar to a boat, a flat bottom surfboard is also designed to ride on the surface. The flat bottom surfboard encounters resistance when a body of water, such as chop or a ledge, enters its path. In choppy, rough, and extreme conditions, the flat bottom may cause a surfboard to stop.

The Bow Wave

​    As any marine vessel moves, it pushes water.  Energy is transferred to water by the vessel.  Water builds in successive waves one on top of the other, ahead of the vessel.  This generates a wave in front of the bow, called a bow wave.  This wave is pushed aside and around the vessel.  All vessels create waves as they push against water's resistance.  As bow waves are created, resistance is over come.  Energy or power keeps a vessel moving as it parts water.    This energy is transferred and continues as a trailing  wake.  The entire cycle is wave making resistance. Boats create both a bow and a stern wave.  Note the dual wake in pic 16.

PIC 15                                                                                                                       PIC 16

PIC17                                                                                                                       PIC 18

A speed boat planes at optimum speed with most of its bow above the water. These hulls only initially push a bow wave. Vessels with planning bottoms lose their bow wave when they attain planning speed.  The bow lifts out of the water hydro dynamically. This reduces the drag associated with a bow wave.   Similarly a flat bottom windsurfer planes in the same way.   The windsurfer, like a motorized boat, can overcome resistance with additional thrust from its sail.  The windsurfer planes with its bow out of the water.  Surfboards plane identically, usually producing a stern or rear wake.  No forward wake is generated when its bow is out of the water.  The surfboard differs in that it cannot generate additional energy or thrust.  It has to use the Kinetic Energy it carries.

Hydrodynamic Lift

Hydrodynamic lift is the force that supports a planning water ski, wake board, or surfboard.  Neither a ski nor wake board will support the weight of a rider when it is floating still in water.  It is difficult to stand up on either one when it is not moving.  As the ski or wake board is propelled, it is lifted hydro dynamically on the water by speed.  It becomes stable when fully planning.

The surfboard planes in the same manner.  During the single fin era, surfer stood and planned forward of center.  Boards were narrower in the tail and wider forward.   This allowed surfers to ride further toward the nose,  Today the wide point on surfboards is further aft.  Surfers plane of the back half of their boards.  A flat aft tail section acts like a planning pad.  The forward half of the surfboard is out of the water and usually free of water contact.  Maximum speed can be achieved when the bow is out of water.  When the bow lifts out of water the bow wave dissipates.  Speed is optimized when the bow no longer pushes water. Lift is generated by speed on a flat surfaces.  Water needs time to move.  Time is not available with fast moving objects on water"s surface.  Thus water remains in place, providing hydrodynamic lift to surfers.  In vertical maneuvers and steep drops, the nose is vulnerable to impact with the wave or chop.   On impact, hydrodynamic pressure is exerted on the nose rocker underside, producing a reverse thrust.  Many surfers are catapulted by hydrodynamic pressure against the nose bottom.

On a flat bottom, the bow directly pushes a bow wave forward, ahead of the board in the surfer's path.   The bow wave formed would be similar to the wave produced on initial take off, pictured below.  Peter Mel is just getting into the wave and is not yet at optimum planning speed.  In the video, the bow wave is visible initially and disappears when the board hydro dynamically planes.

A flat bottom surfboard is similar to a table top. Both need a flat water conditions to move effectively.  In the photo below a bow wave is produced under the table top.  Although not visible the bow wave spans the width of the table.  The bow wave is small due flat water conditions and minimal water displacement of a flat bottom.   The table planes on the surface.

​​

pic 22

Water vessels go through three phases of movement. The order may vary and repeat as a ride progresses.  Three basic phases follow as applied to surfboards:

1.   Displacement mode, the initial phase when a board starts moving.

At low speeds, a surfboard will displace water regardless of hull

shape and bow design. The board is pushing water and producing a

bow wave.  In this mode the board is moving between two waves,

the bow wave and the stern wave.  The bow wave dissipates as the

board transitions and nose lifts.  The displacement mode is not to be                                          confused with a displacement hull shape.

2.  Transition mode, the board starts to accelerate with a slight nose up

attitude.  It is not at optimum speed.  The bow wave starts to

disappear.  The board is pushing less water.

3.   Planning mode,  the board is moving at optimum speed.  The bow is

out of the water.  The bow wave is gone. only a trailing wake follows.  The

board is not longer pushing water.  It is planning on the water surface.

During bottom turns and cutbacks, a surfboard goes through a transition phase.  In a reentry or aerial landing, it is back in a displacement phase.  The surfboard is constantly going through phases.  The best surfboard design is one that progresses through the phases fluidly.  The board over comes each episode of resistance.  This is in the given conditions and with the surfers' design preference.  Most surfboards will work in perfect conditions, not many will perform in large choppy or challenging conditions.

At the start of a ride a surfer generates a forward wave called a bow wave; and an aft wave known as a trailing wake.  . As a surfer picks up speed, the bow wave dissipates and only a trailing wake follows. With hydro dynamic lift, a surfboard planes on its stern or rear end.  The bow and nose are out of water, and the bow wave disappears.  In the next video, note the bow wave that precedes a beautiful ride by Brett Barley, video from YouTube.

Modern surfing has disrupted the sequencing of movement modes.  Movement does not progress from displacement to transition to planning.  Surfers are transitioning in the air.  In aerial maneuvers and air drops, they move from planning to displacement mode.   The flat bottom board does not perform efficiently, in this reverse sequence. It is designed to plane on the surface. Flat bottoms can only displace water at lower speeds.  It requires gradual transition to high speed planning.  It is efficient in clean conditions. A flat bow must clear chop, pockets, wakes and the wave bottom.  When flat bottom impacts water at high speeds, it cannot move water fast enough.

The bow leads the board and paves the way through obstacles in the wave.  Chop, pockets or the wave bottom only initially inhibit performance.  Water moves up a large hollow wave at high speeds, while a surfboard moves downward.   When a flat surface contacts rapid streaming water, it has a damming effect.  The bow tries to hold back the water flow.  It immediately creates resistance and stops the speeding board.

Moving at high speeds, and nearly airborne, surfers land on varying sections of their surfboards with high impact.  They land on their nose, tail, and midsections.  Tail landings on smaller boards are successful in aerial maneuvers. In larger waves, on bigger boards, the success rates is not as high.  The tail will penetrate water much like the nose.  This is due to the rider’s weight and lower board volume at each end.  A flat bow cannot penetrate water a high speed and causes deceleration.  In smaller waves surfers land on the nose of their boards, then use their weight to sink and spin the board around.  Two examples of tail landings follow.       From Surfline.com surflinetv greatest wipe outs

vid 14 &  15

Cold water maybe a factor in the first vid.

The second is in warmer Maui waters.

In this normal progression, a board moves seamlessly   The bow pushes water out of the boards path, in the form of a bow wave.  The rest of the board follows until it begins to plane.  Then the bow lifts out of the water.  Most bows are flat, at lower speeds the flat bow moves well.  At high speeds more water must be moved or displaced, especially if a boards gets airborne.  The bow becomes a landing pad, due to the angle of descent and gravity.  In a late takeoff with an airborne drop, a bow wave can stop movement.  A flat bow with high rocker may not move enough water out of the way, fast enough to allow movement.  A speeding board can get stuck behind its own wake.  Due to cohesion this wake can extend very deep. The board is pushes against hydrodynamic force and stalls in the displacement mode.  A Vee or round bow cushions the landing and allows the board to transition, possibly even planning again.

Kinetic Energy

. Energy cannot be destroyed.  It is transferred from board to water.

. Through movement an object has Kinetic energy.

.  Kinetic energy can pass or do work on anything it hits.

.  It takes equal kinetic energy stop an object that is moving.  An object                                     stops when:  K=K

2

.  Kinetic energy = 1/2mv

A surfer gliding down a wave has energy similar to a skateboarder, rolling down a hill.  Both riders with kinetic energy continue moving through the air when their boards stop.  Both use gravity as opposed to a motor and have no additional thrust available.  Both have kinetic energy, due to movement, which is a function of mass and velocity.

2

K=1/2mv

K= Kinetic Energy     m=mass,  v= speed  mass  = bullet weight and volume

The measure of speed and mass is difficult, especially for water.  Without working the equation, the value of K increases when both Mass and Velocity increase.  The higher the value of K the greater the impact a surfboard will have on water.   This correlates to the amount of resistance or drag it creates.    More specifically the resistance wave or bow wave that it generates. In much simpler terms, the size of the splash a surfboard generates when it hits water.

Hulls

There are many surfboard hull shapes; most can be classified into three categories.  Each category has conditions which optimize performance.

The first is the Planning Category.  Surfboards which are designed to ride on the water surface are planning boards.  These are generally flat bottom with or without concaves and channels for added lift. The flat bottom generates hydrodynamic lift with speed.  This board works well in smooth conditions, planning on its tail.  The flat bottom also performs as a wing, supporting a rider in flight.  The flat bottom is not the best for high impact flat landings.   The Bob Simmons' Hydro Dyamic Planning Hull was an early example.

The second hull category is Displacement.  The bottoms are usually round or vee, thus: the board rides lower in the water.  At top speed it planes a little slower than a planning hull.  It can be more controllable, in chop and free falls, absorbing impact.  Where flat bottoms stall in flat landings, this bottom keeps moving.  In high winds this hull spills air and generates less lift, penetrating where a flat bottom gets pushed or held back.  The following picture is of a Displacement Hull.

Both Round and V Bottom surfboards have origins in the past.  Bob Simmons introduced round bottoms in the 40's. The old Simmons hydrodynamic planning hull had a higher rail line from nose to tail. The rails were called 50/50, because the top and bottom met in the middle of the rail.  The board had belly throughout most of the hull. Some boards ridden by Greg Noll had a displacement shape or roundness to the tail.

Pic 25

There are advantages to this design.  V BottomTails or Round Bottom Tails cannot displace water ahead of the board, however; there are situations when  water must be displaced from the middle of the board.  It is also possible that the slightly lower speeds of these bottoms, may also help control rapid deceleration in chop.  The disadvantage is rail does not hold a steep wave well and tends to roll and slip.

The final hull category is Semi Displacement.  Combining the front half of a Displacement board with the aft half of a planning board produces a hybrid, Semi-Displacement board.  The bow is usually rounded, Vee'd or both.  The aft half underside is usually flat or slightly concaved.  This board displaces water on impact, pushing it aside out of its path.  Absorbing impact, it can transition and recover to get back on a plane.  It planes on its aft section like a planning hull.  It is as fast as a planning hull at top speed and will not stall in chop or in flat landings.  The forward underside spills air and and allows wind penetration and wave entry on take off.  The flat underside section of the board can still act as a wing in aerial maneuvers.   Pictures of Semi-Displacement Hulls follow.

A round bottom bow displaces water and absorbs impact.  It prevents the board from stopping.  A V-Bottom bow will also yield a similar performance, with less loss of speed.  A deep V, can cut through chop and hold the wave better.  On the down side the V may penetrate and bow may submerge deeper into the water.  This may be controlled by shaping the Vee to transition to a flat section, or shaping steps into the bow.  These are called chines. Chines are used on many boats.  They give a hull lift and may keep a surfboard from pearling deeply.

Limited editions of V noses were shaped for bigger waves starting in the 70's. In the 80's Maurice Cole and Tom Curren developed the reverse V surfboard, with V under the forward foot and flatness in the tail.  This design was very far ahead of its time.  They claimed the board cut through water like butter.

When chops are large, more displacement may be required, meaning more hull depth.  The depth of a surfboard's displacement ability is limited to the thickness of the surfboard.  The surfboard nose being very thin, limits the amount of water it can displace.  It may not be able to displace enough water to keep the board  moving.  A surfboard with a thick nose may have more displacement potential but limits performance.

Flat bottom surfboards being planning hulls, are misconceived as the fastest bottoms.  All surfboards plane with their bows out of the water.  If the bow enters the water, at planning speed, the board slows. This is true for all boards.  Flat bottoms slow as they enter the displacement mode.  A displacement shape or semi displacement shape transitions and keeps moving.

On a steep wave, water is moving up its face.  The steeper and hollower the wave the faster water moves.  If a speeding flat bow enters this counter flow, it rapidly decelerates and may stop.  The flat bottom blocks and pushes water directly ahead in its path.  The flat surface is creating lift, which can push the board backward. A displacement shape, round or vee bow, can avoid this predicament.  The shape diverts water out of board's path.  In the photo below the red lines indicate fast moving water.

Pic 29

Solution: Semi Displacement Hull with Moderate Nose Rocker

The solution to prevent surfboards from abruptly stopping at high speed is less rocker, a round or Vee bow and a planning aft section.  A semi displacement hull is the better design.  It combines a planning aft hull with a displacement bow.  Surfing evolution is directing designs toward semi-displacement hulls.  A Vee or round bow will push water out of the surfboards path at high speed.  The surfer can progress further.  This is a good design for modern big wave boards.  It planes on the water surface and displaces water with its bow.  Modern boards often land on their bows in a free fall.  This design cushions impact, so the rider can transition to regain speed and control.

The explosion of stand up paddling, worldwide, has brought new hull designs for various conditions.  The displacement hull was introduced to stand up paddlers for use in choppy conditions. This design is borrowed from canoes, kayaks, boats and paddle boards.  The displacement hull is not usually ridden in large surf.  The bulky nose design is similar to a submarine.  This may cause the hull to submerge like one on a large wave.  The design efficiently glides through chop.  Some features of this board may be incorporated in surfboard designs of the future.