Patent Publication Number: US-11028819-B2

Title: Inertial water column wave energy converter

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This continuation application is based on U.S. Ser. No. 16/234,295, filed on Dec. 27, 2018, claims priority from U.S. Ser. No. 62/613,260, filed Jan. 3, 2018 and U.S. Ser. No. 62/614,419, filed Jan. 7, 2018, incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     Very large amounts of energy are available in the waves that traverse the surface of the world&#39;s oceans. Few if any inventions of the prior art have permitted the capture and beneficial use of this energy in a manner that is both economical and robust to ocean storms. 
     The disclosed wave energy converter is both economical and robust, requiring a relative economy of structural material and having few moving parts. 
     SUMMARY OF THE INVENTION 
     The present invention is a floating wave energy converter that converts wave motion into electrical power when it oscillates vertically in response to the passage of ocean waves. Vertical oscillations of the wave energy converter structure can be out of phase with those of a volume of water located inside one or more typically open-bottomed, vertically-oriented tubes that form part of the structure and descend downwardly into the body of water on which the structure floats. In some embodiments, a volume of air is periodically pressurized and compressed between the aforementioned volume of water and a rigid upper wall or ceiling of an enclosure of the structure, thereby being driven out of the enclosure through air turbines, and (in some embodiments) one-way valves permit air to enter the enclosure freely. A hollow void of the structure, near the nominal waterline of the structure, is completely or partially filled with water (e.g. seawater) to contribute significant mass to the structure and increase the momentum associated with its vertical oscillations. In some embodiments, the hollow void can be at least partially evacuated, causing the structure to vertically rise out of the water to change its waterplane area. In some embodiments, one or more annular jackets around the one or more vertically-oriented tubes are also filled with water (e.g. seawater) to contribute further mass to the structure and further increase the momentum associated with its oscillations. In some embodiments, the structure can propel itself across a body of water using directed lateral expulsions of pressurized air (including, but not limited to, air that has passed through turbines of the embodiment). 
     This disclosure, as well as the discussion regarding same, is primarily made in reference to ocean wave energy converters of the types disclosed and discussed. However, many of the of the parts, systems, devices, mechanisms, etc., disclosed herein, and utilized in the design of the disclosed energy device embodiments, may have application to other devices, systems, and/or mechanisms, and/or to the solution of other problems, and the scope of the current disclosure extends to these components, as well as to the energy device embodiments that contain them. 
     The current disclosure includes many different embodiments, and variations of embodiments, of a novel device that extracts energy from ocean waves. Each of the following device features, behaviors, and/or attributes, is represented by, incorporated within, and/or associated with, at least one embodiment of the current disclosure: 
     1. Buoy 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes a buoy in order to keep at least a portion of the device adjacent to the surface of a body of water. The buoy is located at an upper portion of the disclosed device. In some embodiments, the buoy has a bulb-like, conical, and/or hemicylindrical shape. When the device is in position in a body of water, a water-plane area of the buoy is typically larger than the (combined) horizontal cross-sectional area(s) of the water tube(s) of the device, unless the device is in an elevated (storm-protection) mode. Buoys of the current disclosure include, but are not limited to: flotation modules, flotation platforms, hulls. 
     Buoys of the current disclosure may include, but are not limited to, those which are composed and/or fabricated of, and/or may incorporate, include, and/or contain: air-filled voids, foam, wood, bamboo, steel, aluminum, cement, fiberglass, and/or plastic. 
     Buoys of the current disclosure may include, but are not limited to, those which are fabricated as a substantially monolithic body or interconnected assemblage of parts, e.g., of which individual parts may not be positively buoyant. They may also be fabricated as assemblies of positively buoyant sub-assemblies, e.g., of buoyant canisters or modules. 
     Buoys of the current disclosure include, but are not limited to, those which displace water across and/or over areas of the surface of body of water as small as 2 square meters, and as great as 4,000 square meters. 
     Buoys of the current disclosure include, but are not limited to, those which have a nominal, resting draft as shallow as 10 cm, and as deep as 30 meters. 
     Buoys of the current disclosure include, but are not limited to, those which have a horizontal cross-sectional shape (i.e., a shape with respect to a cross-section parallel to the resting surface of a body of water) that is approximately: circular, elliptical, rectangular, triangular, and hexagonal. 
     Buoys of the current disclosure include, but are not limited to, those which have a vertical cross-sectional shape (i.e., a shape with respect to a cross-section normal to the resting surface of a body of water) that is approximately: rectangular, frusto-triangular, hemi-circular, semi-circular, and semi-elliptical. 
     2. Water Tube 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes a tube, cylinder, channel, conduit, container, canister, object, and/or structure, i.e., a “water tube,” an upper end of which is nominally positioned above the mean water line of the device, and a lower end of which is nominally positioned at some depth below the surface of the body of water (e.g. 20 m, 40 m, 60 m, 80 m, 100 m, 150 m, 200 m and/or near, adjacent to, and/or below, a wave base of the body of water on which the embodiment floats). 
     Water tubes of the current disclosure include, but are not limited to, those which have an approximately circular, square, teardrop-shape, ovular, and/or rectangular horizontal cross-section, i.e., a cross-section through a plane normal to a longitudinal axis of the tube. 
     Water tubes of the current disclosure include, but are not limited to, those which have an internal channel, e.g., through which water and/or air may flow, with an approximately circular horizontal cross-section, i.e., a cross-section through a plane normal to a longitudinal axis of the tube, of approximately constant area and/or shape. However, water tubes of the current disclosure also include, but are not limited to, those which have an internal channel, e.g., through which water and/or air may flow, with a variable, inconsistent, and/or changing, cross-sectional area, i.e., a variable, inconsistent, and/or unequal, area with respect to at least two cross-sections through a plane normal to a longitudinal axis of the tube. 
     Water tubes of the current disclosure include, but are not limited to, those which are fabricated, at least in part, of: steel, and/or other metals; one or more types of plastic; one or more types of fabric (e.g., carbon fiber or fiberglass); one or more types of resin; and/or one or more types of cementitious material. 
     Water tubes of the current disclosure include, but are not limited to, those which are, at least in part, and/or at least to a degree, flexible with respect to at least one axis, as well as those that are, at least in part, rigid and/or not flexible with respect to at least one axis. 
     Water tubes of the current disclosure include, but are not limited to, those which are comprised of tube walls of approximately constant thickness and/or strength; as well as those which are comprised of tube walls of variable, inconsistent, and/or changing, thicknesses and/or strengths. 
     Embodiments of the current disclosure incorporate, include, and/or utilize one or more water tubes, and the scope of the present disclosure includes embodiments that incorporate, include, and/or utilize different numbers, and/or any number, of water tubes. 
     3. Air Turbine 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes “air turbines,” i.e., devices and/or mechanisms that cause a shaft to rotate in response to the passage of air through a channel. 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes a “mono-directional air turbine” that causes a shaft to rotate in a first direction, and/or with a first torque, and/or a first rate of rotation in response to the passage of air through a channel in a first direction of flow, but causes that shaft to rotate in a second direction (or not rotate), and/or with a second torque (or no torque) and/or a second rate of rotation (or no rotation) in response to the passage of air through the channel in a second, e.g., opposite, direction of flow. 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes a “bi-directional air turbine” that causes a shaft to rotate in a first direction, and/or with a first torque and/or a first rate of rotation in response to the passage of air through a channel in a first direction of flow, and causes that shaft to rotate in the same first direction, and/or with torque that is approximately equal in magnitude to the first torque and/or causes that shaft to rotate at a rate of rotation that is approximately equal to the first rate of rotation in response to the passage of air through the channel in a second, e.g., opposite, direction of flow. 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes “air turbines” that are of known types, including, but not limited to, the following types: 
     Wells turbines 
     Wells turbines with guide vanes 
     biplane Wells turbine with guide vanes 
     contrarotating Wells turbine 
     Impulse turbines 
     Impulse turbines with guide vanes 
     McCormick counterrotating turbine 
     Cross-flow turbines 
     Savonius turbines 
     The scope of the current disclosure includes embodiments that incorporate, include, and/or utilize “boundary layer effect turbines” including, but not limited to, those of the “Tesla turbine” design. 
     Embodiments of the current disclosure incorporate, include, and/or utilize one or more turbines, and the scope of the present disclosure includes embodiments that incorporate, include, and/or utilize different numbers, and/or any number, of turbines. 
     4. Ducted Turbine 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes an “air turbine” positioned within a constricted portion of a water tube, or extension of a water tube. By positioning an air turbine in a constricted portion of a tube through which air will flow, the speed of the air is increased thereby facilitating the efficient extraction of power from the flow. 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes “air turbines” positioned within cowlings, tubes, and/or shrouds, that are of known types, including, but not limited to, the following types: 
     
       
         
           
               
               
               
             
               
                   
               
             
            
               
                   
                 ducted turbines 
                 uni-directional ducted turbines 
               
               
                   
                 shrouded turbines 
                 bi-directional ducted turbines 
               
               
                   
                 venturi shaped ducted turbines 
                   
               
               
                   
                 diffuser-augmented wind turbines 
               
               
                   
               
            
           
         
       
     
     An embodiment of the current disclosure incorporates, includes, and/or utilizes “air turbines” positioned within tubes, and/or portions of tubes, that comprise constrictions of known types, including, but not limited to, the following types: 
     
       
         
           
               
               
               
             
               
                   
               
             
            
               
                   
                 venturi tubes 
                 nozzles 
               
               
                   
                 flow nozzles 
                 orifice plates 
               
               
                   
                 Dall tubes 
                 venturi nozzles 
               
               
                   
               
            
           
         
       
     
     Embodiments of the current disclosure incorporate, include, and/or utilize one or more constricted tubes, ducts, and/or ducted turbines, and the scope of the present disclosure includes embodiments that incorporate, include, and/or utilize different numbers, and/or any number, of constricted tubes, ducts, and/or ducted turbines. 
     5. One-Way Valve 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes “one-way vents,” and/or “one-way valves,” i.e., devices and/or mechanisms positioned within, and/or in the path of, a channel that respond to higher pressure within the channel on a first side of the vent by allowing air to flow in a first flow direction, at a first rate of flow, from the first higher-pressure side to a lower pressure side; and, conversely, that respond to higher pressure within the channel on a second, i.e., opposite, side of the valve by allowing air to flow in a second, i.e., opposite, direction, at a second rate of flow which is less than the first rate of flow (or zero). Typically, and nominally, a one-way valve will only allow air to flow through the respective channel when the pressure is relatively higher on one side of the valve, but will not allow air to flow when the pressure is relatively higher on the other side of the valve. 
     An embodiment of the current disclosure incorporates, includes, and/or utilizes “one-way valve” that are of known types, including, but not limited to, the following types: 
     
       
         
           
               
               
               
             
               
                   
               
             
            
               
                 ball check valves 
                 diaphragm check valves 
                 reflux valves 
               
               
                 Belleville valves 
                 duckbill valves 
                 retention valves 
               
               
                 check valves 
                 in-line check valves 
                 stop-check valves 
               
               
                 clack valves 
                 lift-check valves 
                 swing check valves 
               
               
                 clapper valves 
                 non-return valves 
                 umbrella valves 
               
               
                 cross-slit valves 
                 pneumatic non-return  
                 wafer check valves 
               
               
                   
                 valves 
               
               
                   
               
            
           
         
       
     
     The scope of the current disclosure includes embodiments that incorporate, include, and/or utilize “solid-state check valves” including, but not limited to, those of the “Tesla valve” (i.e. “Tesla valvular conduit”) design. 
     Embodiments of the current disclosure incorporate, include, and/or utilize one or more one-way valves, and the scope of the present disclosure includes embodiments that incorporate, include, and/or utilize different numbers, and/or any number, of one-way valves. 
     6. Power Take Off (PTO) 
     The scope of the current disclosure includes embodiments that include, incorporate, and/or utilize, air turbines that are directly and/or indirectly connected to PTOs including, but not limited to, those comprising: 
     an electrical generator 
     a pump (e.g., of air or water) 
     a gearbox and rotatably connected electrical generator and/or pump (e.g., of air or water) 
     a hydraulic ram and/or piston, and, 
     a cam shaft that is operatively connected to a hydraulic ram and/or piston; 
     The scope of the current disclosure includes embodiments that include, incorporate, and/or utilize, air turbines that are directly and/or indirectly connected to linearly extensible components, and/or elements, of extensible PTOs such as hydraulic pistons, rack-and-pinon assemblies, sliding rods/shafts of linear generators, etc. 
     7. Combinations and Derivative Variations 
     The current disclosure includes many novel devices, devices that are hybrid combinations of those novel devices, and variations, modifications, and/or alterations, of those novel devices, all of which are included within the scope of this disclosure. All derivative devices, combinations of devices, and variations thereof, are also included within the scope of this disclosure. 
     The scope of the present disclosure includes embodiments that include, incorporate, and/or utilize, air turbines, valves, and other means of regulating and/or controlling the flow of air and water, in any combination, and incorporating and/or characterized by any and all embellishments, modifications, variations, and/or changes, that would preserve their essential function and/or functionality. 
     This disclosure, as well as the discussion regarding same, is made in reference to wave energy converters on, at, or below, the surface of an ocean. However, the scope of this disclosure applies with equal force and equal benefit to wave energy converters and/or other devices on, at, or below, the surface of an inland sea, a lake, and/or any other body of water or fluid. 
     All potential variations in sizes, shapes, thicknesses, materials, orientations, and/or other embodiment-specific variations of the general inventive designs, structures, systems, and/or methods disclosed herein are included within the scope of the present disclosure. 
     8. Hyper-Pressurized Air Pocket and Water Hammer 
     The current disclosure includes embodiments that comprises a buoyant (i.e., a buoy) portion, and a water tube. The water tube has an upper end positioned above the mean water level of the body of water on which the embodiment floats, and has a lower end positioned at a depth some distance below the mean water level of the body of water (e.g. 50, 100, or 150 m below). The tube is substantially hollow, providing a vertical channel or conduit for water. 
     An upper end of the water tube, an end that is nominally filled with air, contains at least one exit channel typically including a constricted portion (i.e., a “throat”) of reduced cross-sectional area (with respect to the tube&#39;s average and/or median cross-sectional area). In other words, the water tube has an upper end to which is appended, and/or which incorporates, a constriction, such as a Venturi constriction. 
     A turbine is positioned inside the tube, near the throat, typically where the speed of the flow of air out of the tube is approximately maximal. 
     Rise of Water in Tube Lags Behind Water Outside Tube 
     When the embodiment begins to rise in response to an approaching wave crest, the wave-induced increase in the depth of the water increases the pressure of the water adjacent to the lower end of the water tube which causes water to move into the tube in order to raise the level of the water therein (so as to match the level of the water outside the tube). However, the inertia of the water trapped inside the tube prevents that water from rising instantaneously and in perfect concert with the water outside the tube, i.e., the water that lifts the embodiment. 
     In other words, the water tube partially isolates the water inside the tube from the wave-induced motions of the water outside the tube. The level of the water inside the tube rises (or falls) principally in response to changes in the pressure of the water adjacent to its lower mouth. As the water level rises around the embodiment, i.e., as the depth of the embodiment increases, in response to an approaching wave crest, the pressure of the water at the lower mouth of the embodiment&#39;s water tube also increases. However, in the absence of, and/or isolation from, the effect and influence of the water-driven forces propagated within a wave, the inertia of the water inside the tube prevents it from instantaneously rising and falling in concert with the water outside the tube. 
     As a consequence, the level of the water inside the tube, when measured with respect to the seafloor, or some other stationary reference point, tends to rise relatively slowly. However, with respect to the embodiment rising with an approaching wave, the level of the water inside the tube seems to fall (since it doesn&#39;t rise as quickly as the buoy and tube). 
     Volume of Air Above Water Increases 
     And, as a consequence of the latency between the rise of the embodiment and the rise of the water inside the water tube, the volume of the air-filled portion of the tube increases. The increasing volume of the air gap inside the tube decreases the pressure of the air therein, and, as a result, air outside the tube, having a relatively greater pressure, is drawn in to the upper portion of the tube, in some embodiments through a one-way valve, and in other embodiments through a turbine. 
     The air entering the tube enters at approximately the ambient air pressure of approximately one atmosphere. The air is able to enter freely in some embodiments, with minimal, if any, resistance to that inflow. The free inflow of ambient air to equilibrate the pressure of the expanding air-filled upper portion of the water tube facilitates the ability of the water in the tube to rise slowly (e.g., rather than being aided by the upward force created by the air pocket above the water having significantly lower than atmospheric pressure). 
     Water Rises with Increasing Momentum 
     As the water height around the embodiment continues to rise, e.g., as a wave crest more closely approaches, and the embodiment accelerates upward to keep pace, the water inside the tube begins to accelerate upward, albeit more slowly than the embodiment, due to the effect of the increased pressure of the water surrounding the lower mouth of the tube. The upward acceleration of the water inside the tube imbues that water with a degree of momentum commensurate with its substantial mass. 
     Manifestation of a Water Hammer Effect 
     By the time the embodiment reaches the apex of its heave motion, and as the wave crest is passing underneath, the level of the water inside the tube is still accelerating upward. Then, as the embodiment begins to fall, as the wave crest passes, and a corresponding wave trough approaches, the gravitational weight of the embodiment carries it down in concert with the wave, and the downward momentum of the embodiment grows. 
     As the embodiment accelerates downward, and the water inside the tube accelerates upward, the air in the top of the tube is compressed, and its pressure increases. The tube&#39;s one-way valve (if present) does not allow high-pressure air inside the tube to escape. In order to escape, the high-pressure air must pass through a turbine to which a power take-off (PTO) applies a resistive torque, thereby inhibiting its turning. 
     Typically, the only exit aperture provided to the pressurized air inside the tube is through a turbine, the resistive torque, applied to the turbine by an associated power take off (PTO), of which regulates the rate of the air&#39;s out flow as well as the amount of power extracted from its flow. The turbine extracts power from the outflowing air as the embodiment descends in concert with the descending water level created by the approaching wave trough, and for a short time thereafter while residual high-pressure remains. 
     Preparation for Another Cycle 
     Air escapes through the turbine as the embodiment descends, and eventually the amplified pressure of the air is dissipated, as is the relative upward momentum of the water that helped to produce that pressure. 
     Thereafter, the pressure within the water tube again reaches approximately 1 atmosphere and is approximately equilibrated with the pressure of the ambient air. 
     And, the cycle repeats as air is once again drawn into the tube as the embodiment rises on a new wave. 
     Overview 
     An embodiment generates power by: 
     1) letting air freely enter the water tube when the mass and/or inertia-driven latency of the water inside the tube causes the water inside the tube to rise more slowly than the device (i.e. buoy and tube) as the outside water level rises in response to an approaching wave crest; 
     2) when the water level falls in response to an approaching wave trough, pressurizing the air inside the water tube by compressing it between a falling tube (i.e. the falling “ceiling” or top closed portion or wall of the tube) and a rising level of water inside the tube; and, 
     3) constraining the pressurized air to leave the water tube through a turbine that extracts power from its out flow, thereby energizing a PTO. 
     Some embodiments use a differential and/or unequal resistance to the flow of air in to, versus out of, the water tube to drive the air, and its associated water level, below the ambient water level, and/or the outer water level, thereby increasing the average pressure of the air inside the tube above that of the ambient air, causing the water level in the tube to be driven down and causing the mean water level inside the tube to be lower than the mean water level of the surrounding ocean. 
     Average Water Level 
     In embodiments in which the mean water level inside the tube is pushed down by a high-pressure pocket of air in the tube, the level of the water inside the tube is allowed to rise passively as the embodiment rises. However, it is actively pushed down through the pressurization of the air above it, when the embodiment falls. As a result the average level of the water inside the tube is lower and/or below that of the average level of the water outside the tube (i.e., the mean water level of the body of water on which the embodiment floats, and/or the level that would characterized the body of water in the absence of waves). In some embodiments the internal water level oscillates in a range that, at least for several waves cycles, is spaced from and below the average ambient (outer) water level, i.e. the range in which the internal water level oscillates does not, for at least several wave cycles at a time, include the mean outer water level. 
     9. Hypo-Pressurized Air Pocket 
     The current disclosure includes embodiments that comprises a buoyant (i.e., a buoy) portion, and a water tube. The water tube has an upper end or mouth positioned above the mean water level of the body of water on which the embodiment floats, and that has a lower end positioned at some depth below the buoy (e.g. 50 m, 100 m, 150 m, and/or adjacent to, or below, a wave base of the water). 
     An upper end of the water tube, an end that is nominally filled with air, contains an entry port and/or constricted portion (i.e., a “throat”) of reduced cross-sectional area, with respect to the tube&#39;s average and/or median cross-sectional area. In other words, the water tube has an upper end to which is appended, and/or which incorporates, a constriction such as a Venturi constriction. 
     A turbine is positioned inside the tube, near the throat, where the speed of the flow of air out of the tube is approximately maximal. 
     Rise of Water in Tube Lags Behind Water Outside Tube 
     When the embodiment begins to rise in response to an approaching wave crest, the wave-induced increase in the depth of the water increases the pressure of the water adjacent to the lower end of the water tube which causes water to move into the tube in order to raise the level of the water therein (so as to match the level of the water outside the tube). However, the inertia of the water trapped inside the tube prevents that water from rising instantaneously and in perfect concert with the water outside the tube, i.e., the water that lifts the embodiment. 
     In other words, the water tube isolates the water inside the tube from the wave-induced motions of the water outside the tube. The level of the water inside the tube rises (or falls) principally in response to changes in the pressure of the water adjacent to its lower mouth. As the water level rises around the embodiment, i.e., as the depth of the embodiment increases, in response to an approaching wave crest, the pressure of the water at the lower mouth of the embodiment&#39;s water tube also increases. At least partially isolated from the effect and influence of the water-driven forces propagated within a wave at the surface, the inertia of the water inside the tube prevents it from instantaneously rising and falling in concert with the water outside the tube. 
     As a consequence, the level of the water inside the tube, when measured with respect to the seafloor, or some other stationary reference point, tends to rise relatively slowly. However, with respect to the embodiment rising with an approaching wave, the level of the water inside the tube seems to fall (since it doesn&#39;t rise as quickly as the tube that surrounds it). 
     Volume of Air Above Water Increases 
     And, as a consequence of the latency between the rise of the embodiment and the rise of the water inside the water tube, the volume of the air-filled portion of the tube increases. The increasing volume of the air gap inside the tube decreases the pressure of the air therein to a pressure below the outside air pressure, and, as a result, air outside the tube, having a relatively greater pressure, is driven to enter the water tube through a turbine. 
     In embodiments, the only entry and/or inflow aperture provided to the pressurized air outside the tube is through a turbine, the resistive torque of which, applied to the turbine by an associated power take off (PTO), regulates the rate of the air&#39;s flow in to the tube, as well as the amount of power extracted from its flow. The turbine extracts power from the inflowing air as the embodiment rises in concert with the ascending water level around the embodiment created by the approaching wave crest. 
     The tube&#39;s one-way valve does not allow high-pressure air outside the tube to enter. In order to enter, the higher pressure air outside the tube must pass through a turbine to which a power take-off (PTO) applies a resistive torque, thereby inhibiting its turning. 
     The degree of “suction,” or the difference between the outside air pressure and the pressure of the air inside the tube, is increased by raising the mean water level inside the tube higher than the mean water outside water level. When the buoy and tube are moving upward due to a rising outside water level (i.e. when the buoy is rising on a wave), the water inside the tube is typically moving downward under gravity due to the head pressure created by this elevated internal water level. The water&#39;s substantial downward momentum creates a tendency for the air-filled portion of the tube to maintain a lower-than-atmospheric pressure longer than it otherwise would. 
     Overview 
     An embodiment generates power by: 
     1) when the mass and/or inertia-driven latency of the water inside the water tube causes it to rise more slowly than the tube surrounding it as the water level rises in response to an approaching wave crest, and the pressure of the air inside the water tube falls; 
     2) constraining air to enter the relatively under-pressurized air pocket at the top of the water tube through a turbine that extracts power from its inflow, thereby energizing a PTO; and, 
     3) when the outside water level falls in response to an approaching wave trough, allowing air inside the water tube pressurized by its compression between a falling tube and water level inside the tube to exit the tube freely. 
     This embodiment uses a differential and/or unequal flow of air in to, and out of, the water tube to hold the average internal water level above the average ambient (outer) water level, thereby decreasing the average pressure on the air below that of the ambient air. In some embodiments the internal water level oscillates in a range that, at least for several waves cycles, is spaced from and above the average ambient (outer) water level. 
     Average Water Level 
     The level of the water inside the tube is allowed to fall passively as the embodiment falls. However, it is actively pulled up through the depressurization of the air above it, when the embodiment rises. As a result the average level of the water inside the tube is higher and/or above that of the average level of the water outside the tube (i.e., the mean water level of the body of water on which the embodiment floats, and/or the level that would characterized the body of water in the absence of waves). Some embodiments use a differential and/or unequal resistance to the flow of air in to, versus out of, the water tube to drive the air, and its associated water level, above the ambient water level, and/or the outer water level, thereby decreasing the average pressure of the air inside the tube below that of the ambient air, causing water in the tube to be sucked up and causing the mean water level inside the tube to be higher than the mean water level of the surrounding ocean. 
     10. Neutrally-Pressurized Air Pocket 
     An embodiment of the current disclosure compels air to enter and exit the water tube through a turbine, or a pair of turbines, that extract(s) power from both its inflow and outflow, thereby energizing a PTO. Unlike the “hyper-” and “hypo-” pressurized embodiments discussed above, the water tube of this “neutrally-” pressurized embodiment has an average level of water inside its tube that is approximately equal to the average level of the water outside the tube. 
     Instantiations of these embodiments may utilize separate “uni-directional” turbines for the extraction of power from inflowing and outflowing air, and/or “bi-directional” turbines to extract power from flows of both directions. 
     11. Variable Device Mass 
     The current disclosure includes embodiments in which various “water ballast chambers,” compartments, voids, spaces, and/or containers, within the embodiment may be filled with, and/or emptied of, water, thereby altering the average density of the embodiment, and its average depth (i.e., waterline) in the water on which it floats. 
     By emptying water from one or more of these water ballast chambers, an embodiment can reduce its average density and rise up to a shallower average depth, thereby projecting its upper portions out of the water and above potentially damaging storm waves and/or surges. 
     By adding water to one or more of these water ballast chambers, an embodiment can increase its average density and sink down to a greater average depth, for example, a depth in which it can become more responsive to the waves passing beneath and/or around it (i.e. by exhibiting a greater waterplane area), thereby increasing the amount of power it is able to extract from those waves. 
     12. High-Pressure Air Accumulator 
     The current disclosure includes embodiments in which the upper portion of a water tube is separated by the turbine driven by the flow in to, and/or out of, that tube by an “accumulator” in which high- and/or low-pressure air is trapped and then equilibrated by means of a flow through the associated turbine at a steadier rate than would be possible with a direct, and/or unbuffered, flow. 
     13. Composite and/or Cement-Reinforced Tube Wall 
     The current disclosure includes embodiments in which a water tube is comprised of an internal wall, e.g., made of steel, and an outside wall, e.g., also made of steel, and a gap that is filled, at least in part, with concrete and/or another cementitious material. 
     14. Truss Reinforced Tubes 
     The current disclosure includes embodiments in which a water tube is structurally reinforced and/or strengthened by an exterior truss. Another embodiment includes a water tube is structurally reinforced and/or strengthened by an interior truss, e.g., a truss within a concrete-filled gap between interior and exterior tube walls, and/or a truss within the lumen, conduit, aperture, and/or channel, through which water and/or air flow. 
     15. Flexible Tube 
     The current disclosure includes embodiments in which a water tube is, at least in part, not entirely rigid, and/or in which a water tube contains joints or a composite structure enabling the tube to flex while maintaining circumferential strength (to stay “open,” like a water hose). 
     Alternate embodiments each have a water tube comprised, at least in part, of: 
     a flexible tube; 
     rigid tube segments that are conjoined, interconnected, and/or linked, by means of flexible joints, and/or connectors; 
     a flexible material utilizing rigid circumferential bands to prevent the collapse of the tube while permitting it to bend with respect to its longitudinal axis and a limiting maximal bend radius; 
     an accordion-like extensible material that both allows the tube to flex along its longitudinal axis and allows its length to increase and decrease through flexes of the accordion-like pleats that define its walls. 
     16. On-Board Computing 
     The current disclosure includes embodiments in which a plurality of computers perform computational tasks that may not be directly related to the operation, navigation, inspection, monitoring, and/or diagnosis, of the embodiment, its power take-off, and/or any other component, feature, attribute, and/or characteristic of its structure, systems, sub-systems, and/or physical embodiment. Such an embodiment may contain computers, computing systems, computational systems, servers, computing networks, data processing systems, and/or information processing systems, that are comprised of, but not limited to, the following modules, components, sub-systems, hardware, circuits, electronics, and/or modules: 
     graphics processing units (GPUs) 
     computer processing units (CPUs) 
     tensor processing units (TPUs) 
     hard drives 
     flash drives 
     solid-state drives (SSDs) 
     random access memory (RAM) 
     field programmable gate arrays (FPGAs) 
     application-specific integrated circuits (ASICs) 
     network switches, and 
     network routers. 
     Such an embodiment may contain computers, computing systems, computational systems, servers, computing networks, data processing systems, and/or information processing systems, that are powered, at least in part, from electrical energy extracted from the energy of ocean waves by the embodiment. 
     17. Ambient Cooling of Computers 
     The current disclosure includes embodiments in which a plurality of computers, computing systems, computational systems, servers, computing networks, data processing systems, and/or information processing systems, are cooled by methods, mechanisms, processes, systems, modules, and/or devices, that include, but are not limited to, the following: 
     direct conduction of at least a portion of the heat generated by at least some of the computers, generators, rectifiers, and/or other electronic components comprising the embodiment, to air surrounding the embodiment; 
     direct conduction of at least a portion of the heat generated by at least some of the computers, generators, rectifiers, and/or other electronic components comprising the embodiment, to water surrounding the embodiment; 
     indirect conduction of at least a portion of the heat generated by at least some of the computers, generators, rectifiers, and/or other electronic components comprising the embodiment, to the air surrounding the embodiment by means of one or more fluid media and/or heat exchangers, at least one heat exchanger of which is in contact with air surrounding the embodiment; 
     indirect conduction of at least a portion of the heat generated by at least some of the computers, generators, rectifiers, and/or other electronic components comprising the embodiment, to the air surrounding the embodiment by means of one or more fluid media and/or heat exchangers, at least one heat exchanger of which is in contact with water surrounding the embodiment; 
     18. Remote Exchange of Data and/or Power 
     Exchange of data by means of a fiber optic cable 
     The current disclosure includes embodiments in which one end of a cable is suspended adjacent to the surface of the body of water on which the embodiment floats. The other end of the cable is directly and/or indirectly connected to a computer or other electronic device, component, and/or system, directly and/or indirectly connected at least one other computing device on the embodiment. 
     A vessel, e.g., an unmanned autonomous vessel, can approach the embodiment, secure the free end of the cable, and by communicating through that cable with the associated computer or other electronic device, component, and/or system, on board the embodiment, exchange copious amounts of data with the computer or other electronic device, component, and/or system, on the embodiment, e.g., in order to download the results of a calculation and/or simulation performed on the embodiment, and/or to upload a body of data and/or applications with which to perform a calculation. 
     Embodiments of the present disclosure achieve this remote data exchange capability by means of cables including, but not limited to, the following types: 
     fiber optic cables 
     Infiniband cables 
     LAN cables 
     RS-232 cables, and 
     Ethernet cables. 
     Embodiments of the present disclosure may also exchange data with other computers, vessels, networks, data-relay stations, and/or data repositories, by means of communication technologies including, but not limited to, the following types: 
     Wi-Fi 
     5G 
     radio 
     pulse-modulated underwater sounds, e.g., sonars 
     pulse-modulated lasers 
     pulse-modulated LEDs, and, 
     physical semaphores (e.g., 2D arrays of MEMs). 
     Embodiments of the present disclosure may also exchange data with other computers, vessels, networks, data-relay stations, and/or data repositories, by means of communication channels mediated by, and/or including, but not limited to, the following types: 
     boats and/or other manned surface vessels 
     autonomous surface vessels 
     submarines 
     autonomous underwater vessels 
     planes 
     autonomous unmanned aerial vehicles (AUVs) 
     satellites 
     balloons 
     ground stations, e.g., transmission stations positioned on shore, and, 
     other embodiments of the current disclosure. 
     19. Self-Propulsion 
     The current disclosure includes embodiments in which the embodiment possesses devices, mechanisms, structures, features, systems, and/or modules, that actively and purposely move the embodiment, primarily laterally, to new geospatial locations and/or positions. Such self-propulsion capabilities allow embodiments to achieve useful objectives, including, but not limited to, the following: 
     to seek out optimal wave conditions 
     to avoid adverse wave and/or weather conditions 
     to avoid other ships, vessels, and/or potential hazards 
     to avoid shallow waters, rocks, land masses, islands, and/or other geological hazards 
     to maintain proximity to other embodiments, e.g., so as to exchange data with one another, and/or cooperate in the execution of relatively large computing tasks 
     to provide energy to other vessels, and/or disaster areas in time of emergency, and, 
     to return to port in order to receive inspection, maintenance, repair, upgrades, and/or in order to be decommissioned. 
     Embodiments of the current disclosure may achieve self-propulsion by devices, mechanisms, structures, features, systems, and/or modules, that include, but are not limited to, the following: 
     rigid sails 
     flexible sails 
     Flettner rotors 
     keel-shaped tube chambers 
     rudders 
     ducted fans 
     propellers 
     propeller-driven underwater thrusters 
     directed outflows of air from water tubes utilized as thrust 
     water jets 
     submerged, wave-heave-driven flaps, and 
     sea anchors and/or drogues 
     20. Airfoil-Shaped Tubes and/or Tube Shrouds and/or Cowlings 
     The current disclosure includes embodiments in which a water tube does not have a circular cross-section, but, instead, has an airfoil-shaped cross-section. Another embodiment has a water tube is embedded within an airfoil-shaped casing, shroud, and/or cowling. 
     An embodiment minimizes its drag, and facilitates its motion, e.g., by means of self-propulsion, through the use of an airfoil-shaped or otherwise hydrodynamically-shaped (low drag) water tube and/or outer tube casing, shroud, cowling, and/or enclosure. An embodiment with an airfoil-shaped water tube and/or casing also includes rudders and/or ailerons that allow the airfoil-shaped water tube to be steered after the manner of a keel, or an airplane wing. 
     21. Utilization of Turbine Exhaust as Thrust 
     The current disclosure includes embodiments in which the air flowing out of the air-filled portion of a water tube, e.g. through a turbine exhaust, when the air at the top of the water tube is compressed, is directed laterally in a desirable direction so as to propel the embodiment. 
     22. Pitch-Inhibiting Weight 
     The current disclosure includes embodiments in which a weight is suspended beneath one or more water tubes by flexible cables such that when the orientation of the embodiment deviates from vertical, and/or from normal with the resting, nominal surface of the body of water on which the embodiment floats, then the downward gravitational force of the weight is imparted to the bottom of the water tube, thereby creating a restoring torque, or is imparted to the most raised of two or more water tubes, again thereby creating a restoring torque. 
     Scope of the Disclosure 
     While much of this disclosure is discussed in terms of wave energy converters, including both floating and submerged components and/or modules, it will be obvious to those skilled in the art that most, if not all, of the disclosure is applicable to, and of benefit with regard to, other types of buoyant devices and/or submerged devices, and all such applications, uses, and embodiments, are included within the scope of the present disclosure. 
     Detailed Descriptions of the Drawings 
     For a fuller understanding of the nature and objects of the disclosure, reference should be made to the following detailed descriptions, taken in connection with the accompanying drawings. However, the scope of the current disclosure is in no way limited by the drawings, illustrations, descriptions, and/or embodiments, suggested by, in, and/or with respect to, the following figures and descriptions. The following figures and descriptions are offered for the purpose of explanation and illustration of certain aspects and/or attributes of the current disclosure. Other aspects, attributes, possibilities, and variations will be obvious to those skilled in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  a perspective schematic view of a first embodiment of the present invention; 
         FIG. 2  is a top view of the embodiment of  FIG. 1 ; 
         FIG. 3  is an enlarged, sectional view of an upper portion of the embodiment of  FIG. 1 ; 
         FIG. 4  is a perspective view of a cross section of the embodiment of  FIG. 1 ; 
         FIG. 5  is another perspective view of a cross section of the embodiment of  FIG. 1   
         FIG. 6  is a bottom view of the embodiment of  FIG. 1 ; 
         FIG. 7  is a perspective schematic view of a second embodiment of the present invention; 
         FIG. 8  is a perspective view of a cross section of the embodiment of  FIG. 7 ; 
         FIG. 9  is an elevated, perspective view of the embodiment of  FIG. 7 ; 
         FIG. 10  is a cross sectional view of the upper portion of the embodiment of  FIG. 7 ; 
         FIG. 11  is another cross sectional view of the upper portion of the embodiment of  FIG. 7 ; 
         FIG. 12  is a perspective schematic view of a third embodiment of the present invention; 
         FIG. 13  is another perspective view of the third embodiment; 
         FIG. 14  is an enlarged, sectional view of the embodiment of  FIG. 12 ; 
         FIG. 15  is a plan cut-away view of a valve of the embodiment of  FIG. 12 ; 
         FIG. 16  is a perspective schematic view of another embodiment of the present invention; 
         FIG. 17  is a top view of the embodiment of  FIG. 16 ; 
         FIG. 18  is a perspective schematic view of another embodiment of the present invention; 
         FIG. 19  is a perspective view of a cross section of the embodiment of  FIG. 18 ; 
         FIG. 20  is a top view of the embodiment of  FIG. 18 ; 
         FIG. 21  is a downward cross sectional view of the embodiment of  FIG. 19  taken along line  21 - 21 ; 
         FIG. 22  depicts various cross sectional views of alternative embodiments of water column tubes; 
         FIG. 23  is a perspective schematic view of another embodiment of the present invention; 
         FIG. 24  is a top view of the embodiment of  FIG. 23 ; 
         FIG. 25  depicts side views of the embodiment of  FIG. 23  is operation mode and survival mode; 
         FIG. 26  is a downward cross sectional view of the embodiment of  FIG. 23  taken along line  26 - 26 ; 
         FIG. 27  is a perspective schematic view of another embodiment of the present invention; 
         FIG. 28  is a cross sectional view of the embodiment of  FIG. 27 ; 
         FIG. 29  is a perspective schematic view of another embodiment of the present invention; 
         FIG. 30  is a cross sectional view of the embodiment of  FIG. 29 ; 
         FIG. 31  is a perspective schematic view of another embodiment of the present invention; 
         FIG. 32  is a cross sectional schematic view of another embodiment of the present invention; 
         FIG. 33  is a cross sectional view of the embodiment of  FIG. 32  with different heat dissipation paths; 
         FIG. 34  is a cross sectional view of the embodiment of  FIG. 32  with another different heat dissipation path; and 
         FIG. 35  is another variation of the embodiment of  FIG. 32 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a perspective view of an embodiment of the current disclosure. The illustrated embodiment  100  is of the type described above in the section entitled, “Hyper-Pressurized Air Pocket and Water Hammer.” Especially when water within the embodiment&#39;s water column tube  104  is rising, over pressurized air within the water column tube is driven out through a plurality of turbines  105  positioned in the throats of venturi shrouds. Especially when water within the embodiment&#39;s water column tube  104  is falling, under pressurized air within the water column tube is supplemented and/or equilibrated through the admission of ambient outside air through a one-way valve positioned among the venturi shrouds  105  at the top of the embodiment. 
     Inertial water column wave energy convertor (IWC)  100  is floating in a body of water  101  with waterline  102 . IWC  100  is comprised of two primary components, flotation structure  103  and water column tube  104 . Flotation structure  103  has a concave (and approximately conical) profile which is intersected by waterline  102 . A hollow chamber runs from the bottom of water column tube  104  to the top of flotation structure  103 . This opening, tube, and/or chamber, is shown in detail in  FIG. 4  and allows a column of water to rise and fall within it. Pneumatic power take-off modules (PTOs)  105  cover the top of the hollow water-column-tube opening which penetrates floatation structure  103 . These power-take-off modules each include a turbine that turns a generator when air passes through the respective module&#39;s venturi shroud. Valve  106  is also shown which assists in allowing  104  to rise partially out of the water (causing waterline  102  to be located farther down on water column tube  104 ). 
       FIG. 2  shows a plan view of the same embodiment of the current disclosure illustrated in  FIG. 1 . 
     Pneumatic power take-off modules  105  are shown arranged on top of the hollow chamber  107  positioned within flotation module  103 . The PTOs are each shown to be comprised of a turbine, e.g.,  108 , which rotates when air flows past it. This rotation causes a respective generator, e.g.,  109 , to spin, thereby generating electricity. Each turbine, e.g.,  108 , and each generator, e.g.,  109 , is contained within a respective housing, tube, or shroud, e.g.,  110 , which is shaped like a venturi tube or shroud. The convergent/divergent nozzle shape accelerates air entering the housings, as it flows through the respective turbine blades, and slows the flow exiting the housings, after it has flowed through the respective turbine, while minimizing turbulence. Check (i.e., one-way) valve  111  is shown, which allows air to be inhaled into hollow chamber  107  relatively freely, but which closes if air is exhaled (forced out) of hollow chamber  107 . Instead of exiting the hollow chamber  107  through the check valve  111 , air exiting hollow chamber  107  is routed through PTOs, e.g.,  105 , which enables the respective turbines, e.g.,  108 , to rotate. 
       FIG. 3  shows a perspective cutaway view of the same embodiment of the current disclosure that is illustrated in  FIGS. 1 and 2 . 
     Pneumatic power take-off modules, e.g.,  105 , are shown in a cutaway and/or sectional view. The PTOs are comprised of a turbine, e.g.,  108 , and a generator, e.g.,  109 , contained within a venturi-shroud housing, e.g.,  110 , which is shaped like a venturi tube. Check valve  111  opens to admit higher pressure air from the atmosphere into the hollow chamber  107 . And, check valve  112  provides an alternate path for air to escape the hollow chamber  107  in the event that the pressure in hollow chamber  107  exceeds a preset value. Its operation is further described with respect to  FIGS. 4 and 5 . 
       FIG. 4  shows a perspective cutaway view of the same embodiment of the current disclosure that is illustrated in  FIGS. 1-3 . The funnel- or cone-shaped buoy  103  at the top of the embodiment  100  contains a water ballast chamber  114  that can be filled and/or emptied of water in order to add or reduce ballast within the embodiment, and thereby adjust the depth of the embodiment and the position of its average waterline  102 . In alternate embodiments (not shown but substantially similar to that of the present figure), the water ballast chamber can be subdivided into multiple compartments by dividers or bulkheads, and depending on the configuration of the embodiment, each compartment can be either completely separated from, or alternately can communicate with, others of the compartments. 
     IWC  100  is floating in a body of water  101  with waterline  102 . Flotation structure  103  is shown to contain hollow void  114  which is partially filled with a volume of water ballast  115  (e.g. seawater that has entered hollow void  114 ). Void  114  in flotation structure  103  is continuously connected by a channel to hollow flotation collar and/or annular tube  116  that is defined, at least in part, by interior water tube chamber wall  120  and by exterior flotation collar wall  116 , which is also filled with water ballast. Water can pass through this channel from void  114  to hollow flotation collar  116 . 
     Ballast collar  113  is comprised of concrete, stone, metal, or other ballast material having a density greater than that of the water  101  on which the embodiment  100  floats, and is installed to increase the stability of IWC  100 . 
     Hollow tubular chamber  107  is shown to be continuous through flotation structure  103  and water column tube  104 . A water column with waterline  117  is present in hollow tubular chamber  107  and is continuous with the surrounding body of water through the opening, aperture, and/or mouth, in the bottom of water column tube  104 . Waterline  117  is at a different height than the waterline  102  of surrounding body  101  of water. This is due to tubular chamber  107  having an air pressure greater than that of the external atmospheric pressure, which circumstance comes to pass because of the mode of operation of the shown embodiment of the disclosed device. 
     In this embodiment, during operation internal waterline  117  typically oscillates around a mean waterline (i.e. mean vertical position) that is lower than the external mean waterline (i.e. the mean vertical position of  102 ). And, in some embodiments, during operation internal waterline  117  oscillates in a range that does not overlap/include the external mean waterline over the course of several wave cycles e.g. at least 30 seconds at a time, if not significantly longer. The oscillation of the internal waterline about a mean waterline that is lower than the external mean waterline occurs because “inhaling” through valve  111  (i.e. entry of air to the hollow chamber  107 ) is easier (i.e. less inhibited; experiences a lower pressure drop; experiences less resistance to flow) than is “exhaling” through power take off units  105  (i.e. exit of air from the hollow chamber  107 ). Accordingly, within the internal water column the internal waterline  117  is “pumped” downward by the vertical oscillations of the device caused by the passage of waves. This has the advantage of increasing the pressures across the power take off turbines. 
     As IWC  100  rises and falls on waves in body of water  101 , water column  117  does not tend to oscillate with the same phase as the waves passing by the device  100  because it is isolated from wave action due to water column tube  104  extending to a depth where waves influence water particle motion less acutely. When IWC  100  rises toward a wave crest, water column  117  lags, requiring air to be inhaled through check valve  111 . When IWC  100  falls toward a wave trough, the air inside chamber  107  is pressurized, check valve  111  closes, and air is forced out through PTOs  105 . Water column  117  lags descending as well. This behavior continues, resulting in an oscillatory behavior  118  of waterline  117 . During operation, the amount of pressurized air exhaled is controlled in such a way that chamber  107  is on average pressurized some amount above atmospheric pressure, which forces the mean level of water column waterline  117  to remain below the mean level of waterline  102  of surrounding body of water  101 . 
     Valve  112  is a check valve set to open at a given pressure of air chamber  107  which is higher than typical operating pressures. Higher pressures can be experienced when wave heights increase (e.g. storms, etc.) or when wave periods decrease. When chamber  107  pressure exceeds the opening pressure of valve  112 , air is diverted into void  114  of flotation structure  103 . This forces some of the ballast water  115  to exit, and return to the body of water  101 , through ballast opening  119 . Increasing the amount of air inside flotation structure void  114  and decreasing ballast water  115  allows IWC  100  to float higher in the surrounding body of water  101  (i.e. more of IWC  100  will protrude above waterline  102 , increasing its freeboard). The result of this passive deballasting can be seen in  FIG. 5 . 
     During normal operation, i.e. when the embodiment is ballasted to contain a large amount of ballast water  115  and therefore “rides low” in the water to obtain a relatively large waterplane area, the amount of ballast water in flotation structure  103  can fill a major part of the volume of the flotation structure. For instance, in some embodiments, during periods of operation, enough water ballast is contained within flotation structure  103  and/or within hollow flotation collar  116  that the average density of the device (not counting the mass and volume of the water/air contained within the interior channel of water tube  104 , but counting the mass and volume of the remainder of the structure, including any ballast water therein) is greater than 500 kg per cubic meter, greater than 700 kg per cubic meter, and/or greater than 850 kg per cubic meter. In some embodiments, during periods of operation, enough ballast water is contained within flotation structure  103  and/or within hollow flotation collar  116  that more than 50%, more than 60%, more than 70%, and/or more than 80% of the mass of the structure (again, not counting the mass of the water/air contained within the interior channel of water tube  104 , but counting the mass of the remainder of the structure, including any ballast water therein) is from the mass of the ballast water. 
       FIG. 5  shows a perspective cutaway view of the same embodiment of the current disclosure that is illustrated in  FIGS. 1-4 . 
     IWC  100  is shown floating in a body of water  101  with waterline  102 . Ballast water has been passively pumped out of floatation structure void  114  through ballast opening  119  such that the ballast water&#39;s new waterline is  124 , in buoyancy collar  116 . (In other embodiments, deballasting can occur actively, using e.g. an electrically powered mechanical pump.) The decreased weight of IWC  100  has allowed it to increase its freeboard such that its waterline  102  in the surrounding body of water  101  is close to the bottom of IWC  100 . The waterplane area intersected and/or defined by waterline  102  of the IWC  100  configuration illustrated in  FIG. 5  is smaller than the corresponding waterplane area of the configuration illustrated in  FIG. 4 , thus the motion and/or vertical responsiveness of the IWC  100  configuration illustrated in  FIG. 5  due to waves will be less than that of the configuration illustrated in  FIG. 4  as well. The relatively reduced motion of the configuration IWC  100  illustrated in  FIG. 5  means that less pressure will be developed in chamber  107 . Once the pressure peaks decrease below the pressure setting of check valve  112 , air flow will then predominately pass through PTOs  105 . In this way, IWC  100  has a passive feature to allow it to handle increased wave excitation without overloading PTOs  105  and without subjecting the device to excessive structural loads. When wave excitation has decreased and IWC  100  requires a lower freeboard to continue making power, valve  106  can open (e.g. by electronic control), allowing air inside of flotation structure void  114  to escape and water to flow into buoyancy collar  116 , and floatation structure void  114 , through ballast opening  119 . As more of flotation structure void  114  is filled with water, waterline  102  will move higher on IWC  100  and can, if ballasting continues, eventually resume the configuration shown in  FIG. 4 . 
       FIG. 6  shows a cross-sectional view of the same embodiment of the current disclosure that is illustrated in  FIGS. 1-5 . The sectional plane of illustration in  FIG. 6  is taken across line  6 - 6  in  FIG. 5 . Water tube  117  is formed of inner  121  and outer  121  tube walls, between which is cement and/or another cementitious material and/or mixture of materials. 
       FIG. 6  shows the cross section of water column tube ( 104  in  FIG. 5 ) and its components. The central columnar tube of the IWC ( 100  in  FIG. 5 ) is  120 , which encloses tube and/or chamber  107  which contains water column  117 . Central column  120  is comprised of inner and outer skins  121  (e.g. steel or aluminum), between which is filled structural material (e.g. concrete)  122 . This composite sandwich of materials creates a strong spine around which the components of IWC ( 100  in  FIG. 5 ) can attach to and built out from. Nominally water-filled flotation collar  116  is shown to be comprised of an outer skin  123  and shares its inner skin  121  with the outer wall of central column  120  in the shown embodiment. 
       FIG. 7  shows a perspective view of an embodiment of the current disclosure. 
     Inertial water column wave energy convertor (IWC)  200  is floating in a body of water  201  with waterline  202 . IWC  200  is comprised of two primary components, flotation structure  203  and water column tube  204 . Flotation structure  203  has a hull structure intersected by waterline  202 . A hollow chamber or tube runs from the bottom of water column tube  204 , to the top of flotation structure  203 . This chamber or tube is shown in detail in  FIG. 8  and allows a column of water to rise and fall within it. A pneumatic power take-off module (PTO)  205  covers the top of the upper hollow opening in the hollow tube which penetrates floatation structure  203 . Ballast discharge pipe  206  allows IWC  200  to change its weight and rise partially out of the water (causing waterline  202  to become located farther down, and/or on water column tube  204 ). 
       FIG. 8  shows a perspective cutaway or sectional view of an embodiment of the current disclosure. 
     IWC  200  is shown to have an internal configuration similar to that of IWC  100  shown in  FIG. 4 . Tubular wall  216  establishes, at least in part, a tubular structure with upper and lower mouths through which water tends to oscillate, and an inner wall about which buoyancy collar  207  is positioned. Key differences are that buoyancy collar  207  is no longer continuously connected to floatation structure void  208 . Instead, it has been either sealed as a separate air-filled compartment or filled with a material with less density than water (e.g. structural foam, aerated concrete, etc.) to provide permanent buoyancy. Floatation structure  203  now contains two chambers, void  208 , which is partially filled with water and permanent buoyancy chamber  209 , which is an isolated air-filled void. 
     In this embodiment and others, void  208  has larger internal volume than the volume of (i.e. enclosed inside) chamber  211 . In other words, if void  208  were completely filled with a first fluid, and chamber  211  were completely filled with a second fluid, the volume of the first fluid enclosed in void  208  would be larger than the volume of the second fluid enclosed in chamber  211 . For instance, the volume of void  208  can be 4 times larger than the volume of chamber  211 . 
     Furthermore, in this embodiment and others, the area of the free surface of the ballast water  212  inside void  208  is greater (in fact substantially greater) than the area of the free surface of the column of water enclosed in chamber  211 . 
     Furthermore, in this embodiment and others, a horizontal cross-sectional area of void  208  (e.g. at the location of the free surface of ballast water  212 ) is greater (in fact substantially greater) than the maximal horizontal cross-sectional area of the chamber  211 . 
     Furthermore, in this embodiment and others, the mass of the water inside void  208  is greater than the mass of the embodiment as a whole (the latter excluding the mass of the water inside void  208 ). In other words, the mass of the water inside void  208  is greater than the “dry” or “unballasted” mass of the embodiment. A fortiori, the product of (1) the total interior volume of void  208  (the volume occupied by water plus the volume occupied by air) and (2) the density of water is greater than the “dry” or “unballasted” mass of the embodiment. 
     PTO  205  is a bi-directional turbine (e.g. Wells turbine, impulse turbine, etc.). Air directed through check valve  210  during over pressure events in chamber  211  acts to displace ballast water  212  by forcing it up and out of ballast discharge pipe  206 . In this way, IWC  200  can decrease its weight and achieve a higher freeboard during high energy wave conditions in a manner similar to IWC  100  of  FIGS. 1-6 . In smaller waves, water can be pumped back into ballast discharge pipe  206  and/or water can be admitted to the chamber  208  by opening valve  210 , thereby increasing the volume of ballast water  212 , increasing the weight of IWC  200 , and thereby lowering its freeboard back to  202 . Permanent ballast collar  213  provides additional stability, similar to the permanent ballast collar incorporated within IWC  100  of  FIGS. 1-6 . 
       FIG. 9  shows a perspective view of the same embodiment of the current disclosure that is illustrated in  FIGS. 7 and 8 . 
     Pneumatic power take-off module  205  is shown arranged on top of the hollow chamber  211  (see  FIG. 8 ) in flotation module  203 . The PTO is comprised of a turbine  217  and a generator  218  contained within a venturi-shroud housing  219 , which is shaped like a venturi tube having a constricted portion between its upper and lower mouths. The convergent/divergent nozzle shape accelerates air entering the turbine blades and slows the flow exiting the turbine. 
       FIG. 10  shows a perspective cutaway view of the flotation module  203  of the same embodiment of the current disclosure that is illustrated in  FIGS. 7-9 . 
     IWC  200  is shown in a typical operational configuration: waterline  202  is located on the upper half of flotation structure  203  and flotation structure void  208  is partially filled with ballast water  212 . The nominal resting surface  214  of water column is located below the nominal and/or average waterline  202 , indicating that the uppermost air-filled portion  211  of the tube  216 , is pressurized, which causes airflow through turbine  217 . Similar to the embodiment  100  of  FIGS. 1-6 , in an embodiment, waterline  214  oscillates about a mean vertical position that is lower (e.g. at least 1 meter lower, at least 2 meters lower, or at least 3 meter lower) than the mean vertical position of waterline  202 . And, in some embodiments, waterline  214  oscillates in a range (during at least some periods of operation) that is lower than, and spaced from, the mean vertical position of waterline  202 . (In other embodiments, however, this is not true: in these embodiments, waterline  214  oscillates around a mean waterline having a vertical position at approximately the same vertical level as the mean waterline of waterline  202 .) 
       FIG. 11  shows a perspective cutaway view of the same embodiment of the current disclosure that is illustrated in  FIGS. 7-10 . 
     IWC  200  is shown in its survival configuration: ballast water ( 212  in  FIG. 10 ) has been removed from chamber  208  through the passive pumping of pressured air into the chamber through check valve  210  which forced the water up and out of ballast discharge pipe  206 . Waterline  202  is now located on and about the narrowest section of flotation collar  207 , minimizing the response of IWC  200  to waves due to the significantly reduced waterplane area at the new waterline  202 . Waterline  214  is still below waterline  202  of the surrounding body of water indicating that chamber  211  is still pressurized, thus still inducing air to flow through turbine  217 . 
       FIG. 12  shows a perspective view of an embodiment of the current disclosure. 
     IWC  300  is floating in a body of water  301  with waterline  302 . IWC  300  is comprised of a flotation structure  303  and three water column tubes, e.g.,  304 . Water column tubes  304  are similar in construction and function to water column tubes  104  in embodiment  100  illustrated in  FIGS. 1-6 , i.e. they permit a column of water to move inside them so as to drive air through PTOs  305 , and they can contain internal hollow void(s) (e.g., an annular tubular water-filled void) for holding ballasting water such as buoyancy collar  116  in embodiment  100  in  FIG. 5 , and buoyancy collar  207  in embodiment  200  in  FIG. 8 . 
     Flotation structure  303  has a convex profile beneath waterline  302 . Pneumatic power take-off assemblies (PTOs)  305  are installed over the hollow central tube of respective water column tubes, e.g.,  304 . Water column tubes  304  are braced together with structural members  306 , arranged to form a truss. In general, the operation of this embodiment can be understood as qualitatively similar to that of embodiment  100  illustrated in  FIGS. 1-6 , except that the tripod-like nature of the three tubes  304  enable the structure to exhibit greater stability when deballasted such that the buoy rises above the water surface (e.g. to become less sensitive and responsive to storm waves). 
       FIG. 13  shows a perspective view of the same embodiment of the current disclosure that is illustrated in  FIG. 12 . 
     Pneumatic power take-off assemblies (PTOs) ( 305  in  FIG. 12 ) are comprised of at least one solid-state check valve  307 , at least one air director  308 , and at least one boundary layer effect turbine  309  which is coupled to at least one respective generator  310 . The solid-state check valve  307  is configured to allow air to enter the air director  308 , but not to escape therefrom. 
       FIG. 14  shows a perspective cut-away view of a pneumatic power take-off assembly of the same embodiment of the current disclosure that is illustrated in  FIGS. 12 and 13 . 
     Pneumatic power take-off assemblies (PTOs) ( 305  in  FIG. 12 ) are comprised of at least one solid state Tesla valve  307 , air cowling  308 , and Tesla turbine  309  which is coupled to generator  310 . Also shown is check valve  311 , which is set to a pressure which could be reached in excessive wave conditions, providing a secondary air path to help to avoid damage to the PTO components. 
       FIG. 15  shows a plan cut-away view of a solid state Tesla valve  307  incorporated within a pneumatic power take-off assembly ( 305  in  FIG. 12 ) of the same embodiment of the current disclosure that is illustrated in  FIGS. 12-14 . 
     The internal configuration of solid-state check valve (Tesla valve)  307  utilized in PTO  305  is shown. 
       FIG. 16  shows a perspective view of an embodiment of the current disclosure. 
     IWC  400  is floating in a body of water  401  with waterline  402 . IWC  400  is comprised of a flotation structure  403  and four water column tubes, e.g.,  404 . Each water column tube  404  is similar in construction and function to the water column tube  204  incorporated within embodiment  200  illustrated in  FIGS. 7-11 . Flotation structure  403  has a polygonal profile and is intersected by waterline  402 . Water column tubes  404  are braced together with structural members  405 , arranged to form a truss. Water entering or exiting the bottom of each water column tube  404  must also pass through a respective nozzle  406 , which constricts the hollow central chamber of water column tubes  404  to a smaller diameter at their bottoms. The larger upper diameter and smaller lower diameters of nozzles  406  acts to accelerate water flow exiting the water column tube. The operation of this embodiment with respect to power-generation is similar to previous embodiments. 
     Pneumatic power take-off assemblies (PTOs)  407  are installed over the hollow central tube of each respective water column tube  404  in one of two different configurations. Two PTOs, e.g.,  407 A, are installed vertically in conjunction with pneumatic accumulators  408 . This arrangement allows pulsating air from respective tubes  404  due to wave oscillation to be buffered, smoothed, and/or evened out, to produce a steadier flow of air prior to being passed through respective PTOs, e.g.,  407 A. 
     The two other PTOs, e.g.,  407 B, are installed horizontally on directional flow mounts, e.g.,  409 . The directional flow mounts  409  redirect vertical air flow exiting from the respective water column tubes  404  into a horizontal direction through the respective PTOs, e.g.,  407 B. When air escapes from the horizontal PTO modules  407 B, a thrust is produced, which can accelerate IWC  400 . Directional flow mounts  409  are able to rotate about a vertical axis running through the center of the respective water column tube  404  upon which they are installed. This allows thrust produced by air exiting PTO modules  407 B to be vectored (i.e. the thrust produced can be directed to produce linear and/or rotational acceleration of IWC  400 ) and the embodiment  400  to be steered, e.g., in a desirable direction and/or toward a desirable destination. 
     Junction computation box  410  is installed on, and/or attached to, the flotation module  403  and may contain a variety of electronic equipment, including, but not limited to: computers, routers, memory modules, and energy storage devices, and/or it may pass information and/or data to computation equipment contained in and/or on the structure of IWC  400 . Connected to junction computation box  410 , and extending into the surrounding body of water  401 , is data and power cable  411 . Cable  411  may contain fiber optic, high power, low power, digital signal, analog signal, and/or other types of signal/power/information/data transmission capability. Cable  411  can also be suspended in the surrounded body of water  401  at the surface by flotation device  412  which may be of an inflatable or rigid design. 
       FIG. 17  shows a plan view of the same embodiment of the current disclosure that is illustrated in  FIG. 16 . 
     Pneumatic power take-off assemblies (PTOs)  407  are installed over respective hollow central tubes of water column tubes  404  in two different configurations. Two PTOs  407 A are installed vertically atop pneumatic accumulators  408 . The two other PTOs  407 B shown are installed horizontally attached to directional flow mounts  409 . The directional flow mounts  409  are shown with an angle of rotation relative to buoyancy structure  403 , which allows a rotational acceleration to be imparted to IWC  400  allowing it to yaw in body of water  401 . 
     Junction computation box  410  is shown in this view attached to flotation module  403  with cable  411  extending into body of water  401  with flotation device  412  attached. 
       FIG. 18  shows a perspective view of an embodiment of the current disclosure. 
     The illustrated embodiment  500  is of the type described above in the section entitled, “9. Hypo-Pressurized Air Pocket.” Over pressurized air within the water column tube  501  is driven out through turbines  507  that offer little if any resistance to an outward direction of air flow. However, those same turbines actively resist, and extract power from, air flowing inward to the tube when the air therein is under pressurized. (In alternate embodiments the air outflow function is provided not by said turbines that offer little if any resistance, but instead by check-valves that allow air to flow outward but not inward.) As a corollary of allowing air to flow more freely outward than inward, the mean interior waterline inside water column tube  501  can rise to a level higher than the mean outside waterline  502 . 
     Inertial water column wave energy convertor (IWC)  500  is floating in a body of water  503  with waterline  502 . IWC  500  is comprised of two primary components, flotation structure  504  and water column tube  501 . Flotation structure  504  has a cylindrical shape. Water column tube  501  has a non-axisymmetric shape and is supported by exterior truss structure  505 . A hollow chamber runs from the bottom of water column tube  501 , through the top of flotation structure  504 , above flotation structure  504  inside of chimney  506 . This chamber is shown in detail in  FIG. 19  and allows a column of water to rise and fall within it, similar to the water column tube chamber of IWC  100  illustrated in  FIGS. 1-6 . Pneumatic power take-off modules (PTOs)  507  interface, and/or are arrayed or positioned, in a square grid pattern at the top of the hollow chamber inside chimney  506 . 
       FIG. 19  shows a perspective cutaway view of the same embodiment of the current disclosure that is illustrated in  FIG. 18 . 
     IWC  500  is floating in a body of water  503  with waterline  502 . Flotation structure  504  is shown to be hollow, providing buoyancy for IWC  500 . Flotation sponson  508  is shown to be filled with water, but can be evacuated and filled with air, allowing IWC  500  to rise out of the water during a storm similar to manner of storm protection utilized by embodiment IWC  200  illustrated in  FIGS. 7-11  and shown in  FIG. 11 . The central chamber of IWC  500  is formed by hollow cylindrical tube  510 , around which the components of IWC  500  are attached. Stability weight  509  is installed at the bottom of IWC  500  to lower its center of gravity and ensure stability at any prescribed waterline  502 . Stability weight  509  may be comprised of one or more materials with a density greater than that of water. 
     The column of water, with upper surface  513 , contained in hollow cylinder  510  has an average and/or resting waterline higher than the average and/or resting surface  502  of the surrounding body of water  503 . This is achieved by expelling air with low or little resistance from chamber  512  when the buoy falls toward the trough of a wave, and restricting the inflow of air through the increased resistance provided by the turbine assemblies  507  when rising toward a wave crest. When the average elevation of waterline  513  reaches an equilibrium, or in otherwise normal operating conditions, it will oscillate about an average waterline that is elevated above the mean ocean waterline  502 , i.e. its mean waterline might be as shown in  513 . This oscillation provides the mechanism by which air is pulled through PTO modules  507 . Because the waterline is elevated, it generates a head pressure that provides a downward force tending to drive the water column within tube  510  downward unless actively “held up.” This downward force provides additional suction enabling the pressure differential that drives the turbines to be higher than it otherwise would be. 
       FIG. 20  shows a plan expanded view of the array of PTO modules  507  of the same embodiment of the current disclosure that is illustrated in  FIGS. 18 and 19 . 
     Pneumatic power take-off modules (PTOs)  507  are shown arranged in a square grid configuration at the top of chimney  506  of embodiment  500 . Each PTO is shown to be comprised of a turbine, e.g.,  517 , which spins when air flows passed its blades, a respective rotatably connected generator, e.g.,  516 , whose shaft rotates when turbine  517  rotates, and a respective venturi shroud housing, e.g.,  518 . 
     The shaft rotation of generator  516  produces electricity. Turbine  517  and generator  516  are installed in tube  518 , which has wide ends and a narrow middle, where the turbine is located. This shape profile results in air being accelerated when passing though the turbine, so as to pass through the respective turbine&#39;s blades at a relative increased and high velocity relative to the speed which it entered the respective tube  518  from the ambient atmosphere. The resistance of the generator is minimal when air flows out of central chamber of IWC  500 , but is significant when air is being pulled inside. This behavior means that more electricity is generated when air is being pulled inside IWC  500  than when it is being expelled. 
       FIG. 21  shows a cross-sectional view of the same embodiment of the current disclosure that is illustrated in  FIGS. 18-20 . 
     The section plane of the illustration in  FIG. 21  is taken across line  21 - 21  in  FIG. 19 , and shows the cross section of water column tube  501  and its components. Water column tube  501  is supported by truss structure  505 , enhancing its resistance to bending. The central column of IWC  500  is  510 , which contains tubular chamber  512  in which water column  513  oscillates as IWC  500  moves in response to wave forces. Central column  510  is constructed with inner and outer layers  519  made from a material which is strong in tension (e.g. steel, aluminum, titanium, etc.). A structural material (e.g. concrete)  520  is contained between layers  519  which adds strength to the central column  510 . In some alternate embodiments (not shown),  510  is constructed from a single material, e.g. extruded plastic pipe, and this material can be relatively weak (compared to metal) since it is supported by associated truss structure  505 . Buoyancy sponson  515  is shown to be comprised of an outer skin  508  which is constructed from a material strong in tension similar to layers  519  and its inner boundary is central column  510  outermost layer  519 . 
       FIG. 22  shows cross-sectional views of alternate embodiments of the current disclosure, incorporating alternate water column tubes  501 , where the cross-sectional views correspond to sections of the alternate water column tubes  501  as they appear when taken across the same line  21 - 21  as illustrated in  FIG. 19 . The illustrated cross-sectional views shows some, but not all, of the tube cross-sections that characterize alternate embodiments of the current disclosure, and the scope of the present disclosure includes all such alternate embodiments. 
     Cross-sectional views of alternate shapes, constructions, and features are shown for the water column tube  501 . Any of the embodiments taught in this disclosure, as well as others, can include water column tubes having any of these shapes, and/or any other shape. 
     Water column tube cross-sections  521 - 525 , and the tubes they characterize, all share a construction style wherein the central tube chamber  512 , in which slug of water  513  flows and/or oscillates, has an inner wall  526  and an outer wall  508  constructed from a material which is strong in tension. Both walls  526  and  508  may have a similar shape. Void  515  between walls  526  and  508  can be filled with a material denser than water, lighter than water, water, or air. 
     Water column tube cross-section  521 , and the tube it characterizes, is an elongated shape with a blunt end (on the left) and a fine tail at the opposite side (on the right), and being approximately symmetrical about only one axis and/or vertical plane. 
     Water column tube cross-section  522 , and the tube it characterizes, is an elongated shape with two blunt ends at opposing sides, and being approximately symmetric about two axes. 
     Water column tube cross-section  523 , and the tube it characterizes, is a four-sided polygon, and being approximately symmetric about at least two axes. 
     Water column tube cross-section  524 , and the tube it characterizes, is an n-sided polygon with sides of arbitrary length that may or may not exhibit symmetry about any axis. 
     Water column tube cross-section  525 , and the tube it characterizes, is circle which exhibits radial symmetry about its center. 
     Water column tube cross-sections  527 - 530 , and the tubes they characterize, all share a construction style wherein the central void  512 , in which mass of water  513  moves and/or oscillates, is formed by a composite inner tube  510  similar to  510  and an outer wall  508  of the illustration in  FIG. 21 , and constructed from a material which is strong in tension. Inner tube  510  may not be the same shape as outer wall  508 . Chamber  515  between walls  510  and  508  can be filled with a material denser than water, lighter than water, water, or air. 
     Water column tube cross-section  527 , and the tube it characterizes, is a teardrop shape (i.e. airfoil, aerodynamic, or hydrodynamically shaped). Its inner tube has a circular shape. 
     Water column tube cross-section  528 , and the tube it characterizes, is an oval shape with two blunt ends at opposing sides, symmetric about two axes. Water column tube  528  has an inner tube which is rectangular in shape. 
     Water column tube cross-section  529 , and the tube it characterizes, is a wing shape (i.e. one broad end tapering to a narrow end). The narrow end is an articulating flap  531  which can direct air or water flow in a direction other than along the primary long axis of shape  529 . 
     Water column tube cross-section  530 , and the tube it characterizes, is an oblong rounded shape with rudder features  531  at each end of its long axis. 
       FIG. 23  shows a perspective view of an embodiment of the current disclosure. 
     IWC  600  is floating in a body of water  601  with waterline  602 . IWC  600  is comprised of a continuous body which can be described as having two primary structural features: flotation structure (or buoy)  603  and two elongated water column pylons  604 . Water column pylons  604  are similar in construction and function to water column tube  104  in embodiment  100  of  FIGS. 1-6 . Flotation structure  603  has a flat upper deck with an arched underside profile. The arched underside profile allows the waterplane area of the flotation structure to decrease as it is deballasted out of, and/or above, the water. Water column pylons  604  are braced together with structural members  605 , arranged to form a truss. It will be shown in  FIG. 26  that the elongated water column pylons  604  each contain five individual and separate vertical tubular chambers, each with its own oscillating volume and/or column of water. 
     Pneumatic power take-off assemblies (PTOs)  606  are installed over each respective hollow central tube contained within water column pylons  604 . A rotatable foil-shaped mast  607  is installed on the top deck of flotation structure  603 , allowing IWC  600  to harness ambient wind energy in order to create a thrust vector which can linearly or rotationally accelerate IWC  600  along the surface of water  601 . Maneuverable rudders  608  also provide directional authority to IWC  600 . The elongated shape of pylons  604  also provide directional stability to IWC  600 , acting individually, and together, in a manner similar to that of the keel of a sailboat. 
       FIG. 24  shows a top-down view of the same embodiment of the current disclosure that is illustrated in  FIG. 23 . 
     Teardrop shaped rigid sail  607  is shown rotated to an angle of attack with respect to the wind (not shown) on the top deck of flotation structure  603 . Rudders  608  are also shown angled so as to provide a yawing moment to IWC  600 . Two rows of pneumatic power take-off assemblies (PTOs)  606  pass through and above the top deck of flotation structure  603 . 
       FIG. 25  shows a profile view of the same embodiment of the current disclosure that is illustrated in  FIGS. 23 and 24 . 
     Two modes and/or operational configurations of IWC  600  are shown. The configuration illustrated on the left side of  FIG. 25  illustrates the “primary operational mode” of the embodiment, and has the primary flotation buoy structure  603  intersected by surrounding body of water surface  602 . This condition is achieved by containing and/or incorporating ballast water in primary floatation buoy structure  603  and within closed voids in pylons  604 . 
     However, when wave conditions exceed a predetermined threshold, ballast water is passively or actively removed from primary flotation buoy structure  603  and pylons  604 . This behavior decreases the weight of IWC  600  and allows it to have more of its structure protruding from and/or above the surface  602  of the body of water on which the embodiment floats such that it intersects pylons  604  thereby significantly decreasing the waterplane area of the embodiment. This configuration, illustrated on the right side of  FIG. 25 , is referred to as “survival mode” or “deballasted mode.” 
       FIG. 26  shows a cross-sectional view of the same embodiment of the current disclosure that is illustrated in  FIGS. 23-25 , with the sectional plane of illustration in  FIG. 26  taken across line  26 - 26  in  FIG. 25 . 
     IWC  600  is shown in “survival mode” with the surface  602  of body of water  601  intersecting pylons  604 . This higher freeboard is achieved by evacuating some or all of the ballast water which may be contained within the buoyancy chamber of flotation structure  609 . Also shown are the oscillating water column chambers  610  which extend up to a respective pneumatic power take-off assembly ( 606  in  FIGS. 23 and 24 ) and down and out the bottom of each pylon  604  where they allow water to freely flow in and out of each respective tube from and to, respectively, the body of water  601  on which the embodiment floats. 
       FIG. 27  shows a profile view of an embodiment of the current disclosure. 
     IWC  700  is floating in body of water  701  and is similar in form, function, and behavior to IWC  200  in  FIGS. 7-11 . The primary difference is that water column tube  702  is comprised of sections  704 , connected by elastomeric links  705 . This sectional construction allows water column tube  702  to bend conformally when its upper sections and flotation module  703  are accelerated translationally/horizontally by wave forces. 
       FIG. 28  shows a profile sectional and/or cut-away view of same embodiment of the current disclosure that is illustrated in  FIG. 27 . 
     Sections  704  comprising water column tube  702  have flared ends  706 . These flared ends allow elastomeric links  705  to be clamped around and/or cast around the ends of respective sections  704 , thereby coupling the sections together. 
       FIG. 29  shows a profile view of an embodiment of the current disclosure. 
     IWC  800  is floating in body of water  801  and is similar in form, function, and behavior to IWC  200  of  FIGS. 7-11 . The primary difference is that water column tube  802  is comprised of a flexible central tube  803  (e.g. constructed from an elastomer, polymer, fabric, net, etc.) and is kept round by stiffening rings  804 . The stiffening rings  804  prevent the flexible tube from collapsing inward due to pressure differentials between the inside and outside of water column tube  802 . Stiffening rings  804  would be constructed of a stiff material such as steel, aluminum, PEEK, etc. Constructing the water column tube from flexible materials and sectional stiffeners allows water column tube  802  to bend conformally when its upper portion and flotation module  805  are accelerated translationally by wave forces. 
       FIG. 30  shows a profile cut-away and/or sectional view of the same embodiment of the current disclosure that is illustrated in  FIG. 29 . 
     Stiffening rings  804  are shown to exist on the exterior of flexible central tube  803  comprising water column tube  802 . 
       FIG. 31  shows a perspective view of an embodiment of the current disclosure. 
     IWC  900  is floating in a body of water  901  with water column pylons  902  extending beneath the water surface. Flexible connecting members  903  are attached to each of the pylons  902  and are all connected to weight  904 . Weight  904  is of a substantial mass and provides a restoring torque to IWC  900  whenever IWC  900  pitches or rolls in body of water  901 . 
       FIG. 32  shows a profile cut-away view of the same embodiment IWC  200  of the current disclosure illustrated in  FIGS. 7-11 . 
     A simplified cut-away diagram of IWC  200  of  FIGS. 7-11  is shown floating in body of water  201 . IWC  200  is operating in such a way that the waterline  214  within central column  204  is below the surface of body of water  201 , as described in  FIG. 8 . 
     Computational modules  220 ,  228 - 231  may be installed on the deck of flotation module  203  or inside that flotation structure  203 . Computational modules  220 ,  228 - 231  may receive electrical power from electricity generated by turbine  217  driving generator  218 . Computational modules  220 ,  228 - 231  contain one or more computational processing nodes (CPU, GPU, TPU, ASIC, etc.) and may utilize cooling by exposure to ambient or forced air, conductive cooling through a solid-state heat sink, or fluidic cooling with passive or pumped fluid conducting heat away to a remote heat sink. 
     Computational module  220  is cooled, at least in part, by an external radiator  221  attached directly to the module structure. Computational modules  220  and  228  are cooled, at least in part, by remotely positioned external radiators  223 - 225  in which heat is transmitted to the radiators by means of piping/hoses, e.g.,  222 . Remote radiators may be located on an exterior surface  223  of the IWC  200  (exposed to ambient air/wind), on an interior structure or surface  224  of the flotation module  203  (utilizing the hull as a heat sink), inside of the PTO air flow path  225 , and/or inside of the water column chamber  204  (exposed to moving air  226  and/or moving water  227  and/or both). 
     Multiple computational modules (e.g.  228  and  220 ) may share a heat dissipation path and/or radiator (e.g.  223 ). 
     Computational modules  229 - 231  are mounted directly to a structure and/or surface of IWC  200  so as to directly conduct heat away from the modules. Computational modules  230  and  231  are mounted to, on, and/or against, the central water column structure  204  above or below (e.g.  230 / 231 ) the waterline  214  inside the water column. Computational module  229  is mounted to an interior structure and/or surface of flotation module  203 . In some embodiments, only one of the above described heat dissipation paths or heat exchange locations is used. In some embodiments, multiple heat dissipation paths or heat exchange locations are used. 
       FIG. 33  shows a profile cut-away view of the same embodiment IWC  200  of the current disclosure illustrated in  FIGS. 7-11 . 
     A simplified cut-away diagram of IWC  200  of  FIGS. 7-11  is shown floating in body of water  201 . IWC  200  is operating in such a way that the waterline  214  within central column  204  is below the surface of body of water  201 , as described in  FIG. 8 . 
       FIG. 33  illustrates a configuration of embodiment  200  that incorporates two computational modules that utilize independent heat dissipation paths (e.g.,  222 ), and that incorporates two computational modules  220  and  228  that share a heat dissipation path and/or radiator  223 . 
       FIG. 34  shows a profile cut-away view of the same embodiment IWC  200  of the current disclosure illustrated in  FIGS. 7-11 . 
     A simplified cut-away diagram of IWC  200  of  FIGS. 7-11  is shown floating in body of water  201 . IWC  200  is operating in such a way that the waterline  214  within central column  204  is below the surface of body of water  201 , as described in  FIG. 8 . 
       FIG. 34  illustrates a configuration of embodiment  200  that incorporates four computational modules, e.g.,  220 , that utilize only conductive heat dissipation achieved directly and/or indirectly to the atmosphere and/or to the structure of the embodiment, e.g., to the walls of the buoy  203  and/or to the walls of the water column  204 . 
       FIG. 35  shows a profile cut-away view of the same embodiment IWC  200  of the current disclosure illustrated in  FIGS. 7-11 . 
     A simplified cut-away diagram of IWC  200  of  FIGS. 7-11  is shown floating in body of water  201 . IWC  200  is operating in such a way that the waterline  214  within central column  204  is below the surface of body of water  201 , as described in  FIG. 8 . 
       FIG. 35  illustrates a configuration of embodiment  200  that incorporates only a single and/or consolidated computational module  220  that utilizes a variety of heat dissipation mechanisms including direct conduction of heat to the structure of the embodiment (e.g., at and/or to the upper deck of the flotation module  203 ), and the exchange and/or radiation of heat by and/or through directly mounted  221  and remote radiators. 
     The scope of the present disclosure includes all computational module heat dissipation designs, architectures, mechanisms, methods, schemes, and/or systems, including, but not limited to, those involving phase-changing materials, fans, pumps, and two- or multi-stage heat exchangers.