Patent Abstract:
A vehicle propulsion system having a mount; a rotation shaft oriented substantially normal to a plane of travel of a vehicle; a fixture coupled to the rotation shaft, the fixture being rotatable about a rotation shaft axis of the rotation shaft; and an oar assembly coupled to the fixture; wherein the coupling is coupled to the fixture, wherein the rotation shaft axis is substantially normal to the rotational axis; wherein the coupling is coupled to the fixture to permit rotation of the oar assembly about the rotation axis when the lock is locked.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to vehicle propulsion, and more specifically to human-powered vehicle propulsion, such as human-powered propulsion of a water vehicle. 
     2. Discussion of the Related Art 
     Kayakers and other boaters exhibit a wide range of skill levels, from the recreational kayaker to the professional competitor. Kayaking enthusiasts pursue their sport in a variety of settings, including creeks, rivers, and the ocean. Each of the settings presents unique challenges to the kayaker. 
     In order to kayak effectively, it is essential that the kayaker be able to effectively control the kayak with a minimum of effort; this is no less true for the recreational kayaker than it is for the expert. The essential element in kayak control is the kayak paddle. A kayak paddle that the user can easily and efficiently employ will greatly facilitate control of the kayak. 
     Kayak paddles include a single elongated shaft and two flattened blade portions, which may be either integral with the shaft or coupled thereto. The paddle is usually made of some suitably rigid material such as carbon fiber, wood, aluminum, or plastic. Low weight and sufficient strength to resist the forces imposed upon the paddle are important considerations in the manufacture of paddles. 
     To use a kayak paddle one grips and supports the shaft with both hands, generally perpendicular to the longitudinal axis of the kayak. A blade is inserted in the water near the side of the boat at a point in front of the user. The blade is then pulled backward approximately parallel to the longitudinal axis of the kayak, by backward pressure exerted through the hand closest to the blade in the water, while forward pressure is exerted through the other hand. When the blade has been pulled back to a point beside or just behind the user, it is removed from the water with an upward motion and the opposite blade is inserted in the water in front of the user. The sequence of motions is repeated, creating forces that propel the boat forward through the water. Subtle differences in the amount of force applied and the direction in which it is applied with each stroke are used to steer the kayak and keep it on course. 
     In order to paddle effectively, the kayaker must be able to hold the paddle continuously aloft with both hands while simultaneously twisting, rotating and raising/lowering the blades. This requires some amount of physical strength and coordination. 
     SUMMARY OF THE INVENTION 
     Several embodiments of the invention advantageously address the needs above as well as other needs by providing a vehicle propulsion system and method. 
     In one embodiment, the invention can be characterized as a vehicle propulsion system including a mount for mechanically coupling to a vehicle; a rotation shaft oriented substantially normal to a plane of travel of the vehicle; a fixture coupled to the rotation shaft, the fixture being rotatable about a rotation shaft axis of the rotation shaft; and an oar assembly coupled to the fixture, the oar assembly including a first blade, a first shaft, the first blade being coupled to a distal end of the first shaft, a second blade, a second shaft, the second blade being coupled to a distal end of the second shaft, a coupling interposed between a proximal end of the first shaft and a proximal end of the second shaft and selectively permitting rotation of the first shaft relative to the second shaft about a rotational axis, wherein the coupling includes a lock for locking the first shaft relative to the second shaft so as to prevent rotation of the first shaft relative to the second shaft when the lock is locked, a first adjuster, wherein the first adjuster adjusts the length of the first shaft, and a second adjuster, wherein the second adjuster adjusts the length of the second shaft; wherein the coupling is coupled to the fixture, wherein the rotation shaft axis is substantially normal to the rotational axis; wherein the coupling is coupled to the fixture to permit rotation of the oar assembly about the rotation axis when the lock is unlocked. 
     In another embodiment, the invention can be characterized as a method including mechanically coupling of a mount to a vehicle; orienting a rotation shaft substantially normal to a plane of travel of the vehicle; coupling a fixture to the rotation shaft, the fixture being rotatable about a rotation shaft axis of the rotation shaft; coupling an oar assembly to the fixture, the oar assembly including a first blade, a first shaft, the first blade being coupled to a distal end of the first shaft, a second blade, a second shaft, the second blade being coupled to a distal end of the second shaft, a coupling interposed between a proximal end of the first shaft and a proximal end of the second shaft and selectively permitting rotation of the first shaft relative to the second shaft about a rotational axis, wherein the coupling includes a lock for locking the first shaft relative to the second shaft so as to prevent rotation of the first shaft relative to the second shaft when the lock is locked, a first adjuster, wherein the first adjuster adjusts the length of the first rotation shaft, and a second adjuster, wherein the second adjuster adjusts the length of the second shaft; and coupling the coupling to the fixture to permit rotation of the oar assembly about the rotation axis when the lock is locked, wherein the rotation shaft axis is substantially normal to the rotational axis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of several embodiments of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings. 
         FIG. 1  is a simplified rear view of a kayak with an angle oar. 
         FIG. 2  is a simplified rear view of the angle oar according to some embodiments. 
         FIG. 3  is a simplified rear view of the angle oar according to some embodiments. 
         FIG. 4  is a simplified rear view of the angle oar according to some embodiments. 
         FIG. 5  is a simplified rear view of the angle oar according to some embodiments. 
         FIG. 6  is a simplified rear view of the angle oar according to some embodiments. 
         FIG. 7  is a side cross-sectional view of the central portion of the angle oar. 
         FIG. 8  is a top cross-sectional view of the central portion of the angle oar. 
         FIG. 9  is a side view of the center hub of the angle oar. 
         FIG. 9A  is a side view of the center hub of the angle oar. 
         FIG. 9B  is a side view of the center hub of the angle oar. 
         FIG. 10  is a side view of a cam head adjustment bolt. 
         FIG. 10A  is a bottom view of the cam head adjustment bolt with an offset head. 
         FIG. 11  is a top view of the kayak with the angle oar and a bottom-mounted support. 
         FIG. 12  is a rear cross-sectional view of the kayak with the angle oar and the bottom-mounted support. 
         FIG. 13  is a side cross-sectional view of the kayak with the angle oar and the bottom-mounted support. 
         FIG. 14  is a side cross-sectional detail of the bottom-mounted support. 
         FIG. 15  is a rear cross-sectional view of the bottom-mounted support. 
         FIG. 16  is a top view of the kayak with the angle oar and a top-mounted support. 
         FIG. 17  is a side cross-sectional view of the kayak with the angle oar and top-mounted support. 
         FIG. 18  is a simplified side view of the kayak with the angle oar, the bottom-mounted support, and a stabilizing rod 
         FIG. 19  is a perspective view of the kayak with the angle oar, top-mounted support and the stabilizing rod. 
     
    
    
     Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. 
     DETAILED DESCRIPTION 
     The following description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of exemplary embodiments. The scope of the invention should be determined with reference to the claims. 
     The present invention in accordance with some embodiments provides a kayak paddle with a central support that is not found in present day kayaks. Some embodiments further provide for each paddle to be independently adjustable in length. Additional embodiments further provide for each paddle side to be rotatable to, for example, 4 angles relative to the paddle axis, allowing for the paddle to be adjusted for differing paddling conditions or to be operated with one hand. Some embodiments further provide for paddle blades shaped to allow for paddling in shallow water. In some variations, embodiments further provide for a paddle support mounting system coupled to the kayak floor. This bottom-mounted (or floor-mounted) support system is angled towards the kayak bow along a longitudinal axis of the kayak and provides for adjustment of the central support vertically and relative to the kayak. Some embodiments further provide for a paddle support system mounted to the underside of the foredeck of the kayak. This top-mounted support system is angled towards the kayak bow along a longitudinal axis of the kayak and provides for adjustment of the central support vertically and longitudinally relative to the kayak. The support system angle automatically angles the kayak paddle blades to provide some bite, advantageously keeping the blade in the water through the stroke. The present embodiments further provide for vertical rods that provide anchorage, kayak stabilization and assistance in entering and exiting any kayak or means of conveyance. 
     Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
       FIG. 1  depicts a kayak  100  with an angle oar  102  in accordance with one embodiment installed. The view is looking towards the bow of the kayak with the longitudinal axis being normal to the plane of the page. The angle oar  102  includes a central support with a clevis  104 . A left paddle arm is comprised of a left blade  106 , a left outer tube  108  and a left inner tube  110 . A right paddle arm is comprised of a right blade  112 , a right outer tube  114 , and a right inner tube  116 . A support post  118  (also referred to as a rotation shaft) is shown. The support post  118  is anchored to the kayak. Two examples of support post anchorage, a bottom-mounted anchorage  1302  (as shown in  FIG. 11 ) and a top-mounted anchorage  1800  (as shown in  FIG. 16 ), are described below. The clevis  104  is coupled to the top of the support post  118 . The left blade  106  is coupled to the left end of the left outer tube  108 . The right end of the left outer tube  108  is coupled to the left end of the left inner tube  110  with an adjustable connection. The right end of the left inner tube  110  is coupled to the clevis  104  with a connection that allows for rotation about an axis concurrent with the central hub and approximately normal to the longitudinal kayak axis. The right blade  112  is coupled to the right end of the right outer tube  114 . The left end of the right outer tube  114  is attached to the right end of the right inner tube  116  with an adjustable connection as described below. The left end of the right inner tube  116  is coupled to the clevis  104  with a connection that allows for rotation about an axis concurrent with the central hub and approximately normal (e.g., normal or angled slightly forward of normal, e.g., seven degrees forward of normal) to the longitudinal kayak axis (substantially normal to a plane of travel of a kayak, e.g., a plane of a surface of water on which the kayak is traveling). The shape of the left blade face  120  and right blade face  122  are such that the faces come to a point that aligns with the left outer tube longitudinal axis and right outer tube longitudinal axis, respectively. An upper half and a lower half of the left blade face  120  and an upper half and a lower half of the right blade face  122  have equal planar areas. The upper half and lower half of the right blade face  122  are juxtaposed on opposite sides of the right outer tube  114  and are coplanar with one another. The upper half and lower half of the left blade face  120  are juxtaposed on opposite sides of the left outer tube  108  and are coplanar with one another. 
       FIG. 2  depicts the angle oar  102  adjusted for maximum paddle arm length on each paddle arm and the outer tubes  108 ,  114  aligned on a straight axis. The length of each paddle arm is independently adjustable as described below. 
       FIG. 3  depicts the angle oar  102  adjusted for minimum paddle arm length on each side and the paddle arms aligned on a straight axis. 
       FIG. 4  depicts the angle oar  102  adjusted for minimum paddle arm length on each paddle arm and the left paddle arm is rotated clockwise about the central hub so as to create an angle between the right paddle arm and the left paddle arm. 
       FIG. 5  depicts the angle oar  102  adjusted for maximum paddle arm length on the left hand side and the right paddle arm rotated clockwise. The right side paddle arm is adjusted for minimum paddle arm length. 
       FIG. 6  depicts the angle oar  102  adjusted for maximum paddle arm length on the left side and the right paddle arm rotated clockwise. The right paddle arm is adjusted for maximum paddle arm length. 
       FIG. 7  depicts a vertical section through the central hub of the angle oar  102  in accordance with one embodiment. The center support includes the support post  118 , the clevis  104 , a pivot pin  800  and a clevis lock pin  802 . Shown are a clevis base tube  804  (also referred to as a sleeve), a clevis base plate  806  and a clevis front plate  808 . In one embodiment, the pivot pin  800  is held in place by a set screw  810 . The portion of the left paddle arm shown includes the left outer tube  108  and the left inner tube  110 . A left adjusting spring  812  with a left adjusting button  814  is shown. A plurality of left adjusting holes  816  are shown. A cam head adjustment bolt  818  (also referred to as a cam bolt) is shown coupled to the right end of the left inner tube  110 . The portion of the right paddle arm shown includes the right outer tube  114  and the right inner tube  116 . A right adjusting spring  820  with a right adjusting button  822  is shown. A plurality of right adjusting holes  824  are shown. A sliding bolt lock  826  and a sliding bolt lock spring  828  are located on the right inner tube  116  adjacent to the clevis  104 . 
     Referring next to  FIG. 8 , a horizontal section through the central support of the angle oar  102  is shown in accordance with one embodiment of the invention. The central support portion including the clevis  104  and pivot pin  800  is shown. In one embodiment, the pivot pin  800  is held in place by a set screw  810 . The portion of the left paddle arm shown includes the left outer tube  108  and the left inner tube  110 . A left adjusting spring  812  with a left adjusting button  814  is shown. A plurality of left adjusting holes  816  are shown. The portion of the right paddle arm shown includes the right outer tube  114  and the right inner tube  116 . A right adjusting spring  820  with a right adjusting button  822  is shown. A plurality of right adjusting holes  824  are shown. 
     The bottom tube portion of the clevis  104  fits over and is supported by the cylindrical support post  118 . In one embodiment, the clevis lock pin  802  secures the clevis  104  to the support post  118 . The top of the clevis  104  is shaped to support the pivot pin  800 . In one embodiment, the pivot pin  800  is secured to the left inner tube  110  with a set screw  810 . The right end of the left inner tube  110  has a cylindrical shape with a central hole. The pivot pin  800  goes through the central hole, providing support and rotation for the left and right paddle arms. The set screw  810  bears against the pivot pin  800  so that the left inner tube  110  and pivot pin  800  move together, independently of the clevis  104  and right inner tube  116 . The sliding bolt lock  826  is located in a recess in the left end of the right inner tube  116 . The left end of the right inner tube  116  includes a front outer plate  900  and a rear outer plate  902 , each coupled to an opposite side of the left end of the right inner tube  116 . The outer plates  900 ,  902  are located on either side of the cylindrical portion of the left inner tube  110  and are supported by and may rotate about the pivot pin  800 . The left and right adjusting springs  812 ,  820  are located in the left and right outer tubes  108 ,  114 . The left and right adjusting buttons  814 ,  822  are coupled to the left and right adjusting springs  812 ,  820 . The left and right outer tubes  108 ,  114  have a plurality of left and right adjusting holes  816 ,  824  which align with the left or right adjusting button  814 ,  822 . 
     In one embodiment of the invention, the clevis base tube  804  receives and is supported by the support post  118 , the clevis base tube further being rotatable about a longitudinal rotation shaft axis of the support port  118  when the clevis lock pin  802  is not used. The top portion of the clevis  104  includes two vertical sides located outside of the left and right inner tubes  110 ,  116 . The clevis sides, along with the pivot pin  800 , provide support for the paddle arms and allow for rotation of the paddle arms about the pivot pin axis. In one configuration, the sliding bolt lock  826  is moved to its leftmost position. A portion of the sliding bolt lock  826  is received by a sliding bolt lock hole  904  in the cylindrical portion of the left inner tube  110 . The sliding bolt lock hole  904  is located so that engagement of the lock will align the longitudinal axes of the left and right paddle arms and prevent them from moving relative to one another. The sliding bolt lock spring  828  is sufficiently tensioned to keep the sliding bolt lock  826  in the leftmost position while allowing for a person to slide the sliding bolt lock  826  to the rightmost position when desired. When the sliding bolt lock  826  is moved to its rightmost position, the right paddle arm rotates clockwise until its rotation is stopped by the cam head adjustment bolt  818 . Alternately, when the sliding bolt lock  826  is moved to its rightmost position, the left paddle arm may be rotated clockwise towards the right paddle arm, allowing for a shorter paddle arm profile. 
     In one embodiment, the paddle arms include a button spring mechanism. On the left paddle arm, the left adjusting spring  812  is coupled to the inside of the left inner tube  110 . The left adjusting button  814  is coupled to the left adjusting spring  812  so that the left adjusting button  814  extends through one of the left adjusting holes  816 , locking the length of the paddle arm. The left adjusting spring  812  holds the left adjusting button  814  in place. To adjust the length of the left paddle, the left adjusting button  814  is depressed until the button top is below the left outer tube  108 , allowing the left outer tube  108  to slide relative to the left inner tube  110 . The left outer tube  108  slides to the left or right until the left adjusting button  814  aligns with an alternate left adjusting hole and the left adjusting spring  812  causes the left adjusting button  814  to extend through the alternate left adjusting hole. The difference between the previous left adjusting hole and the current left adjusting hole is the change in left paddle arm length. The right paddle arm is adjusted in a similar way. 
       FIG. 9  depicts a detail of the central portion of the angle oar  102 . Shown are the left inner tube  110 , the right inner tube  116 , the pivot pin  800 , the sliding bolt lock  826 , the sliding bolt lock hole  904 , the sliding bolt lock spring  828  and the cam head adjustment bolt  818 . In one embodiment, the cam head adjustment bolt  818  has an offset cam head adjustment bolt head  1100  (as shown in  FIG. 10 ). The sliding bolt lock  826  is shown in the rightmost position, uncoupling the paddle arms and allowing the right paddle arm to be rotated clockwise. The clockwise rotation is stopped when the right inner tube  116  contacts the cam head adjustment bolt head  1100  of the cam head adjustment bolt  818 . In one embodiment, the cam head adjustment bolt  818  is adjusted one quarter turn so that the allowed rotation is approximately 30° when the maximum head overhang of the cam head adjustment bolt  818  contacts the right inner tube  116 .  FIG. 9A  shows the cam head adjustment bolt  818  adjusted one half turn so that the allowed rotation angle is increased.  FIG. 9B  shows the cam head adjustment bolt  818  adjusted so that the allowed rotation angle is maximized to approximately 40°. 
     Referring next to  FIG. 10 , a detail of one embodiment of the cam head adjustment bolt  818  is shown. The cam head adjustment bolt head  1100  is shown offset from a cam head adjustment bolt shaft  1102 . In one embodiment, the cam head adjustment bolt head  1100  is offset from the cam head adjustment bolt shaft  1102  so that the cam head adjustment bolt head  1100  aligns with the cam head adjustment bolt shaft  1102  at a single point, as shown in  FIG. 10A . A thread locking bead  1104  is shown on the cam head adjustment bolt shaft  1102 . In this embodiment, the cam head adjustment bolt  818  diameter is 5/16″, the cam head adjustment bolt head  1100  diameter is ⅝″, and the cam head adjustment bolt head  1100  thickness is ⅜″. In one embodiment, the cam head adjustment bolt head  1100  has a hexagonal socket drive  1106 . 
     Referring next to  FIG. 11 , one embodiment of angle oar anchorage is shown. A top view shows the kayak  100 , a kayak seat  1300 , the angle oar  102  and a bottom-mounted anchorage  1302 . The bottom-mounted anchorage  1302  contains a plurality of support post cavities  1304 . The support post  118  fits in the bottom-mounted anchorage  1302 , which is coupled to the kayak floor (also referred to as the kayak deck) by plastic welding or other suitable method. The support post  118  may be placed in any of the support post cavities  1304  (also referred to as step holes). 
       FIG. 12  depicts a section through the kayak  100  looking towards the kayak bow. The kayak  100 , angle oar  102 , support post  118 , bottom-mounted anchorage  1302  and support post cavity  1304  are shown. 
       FIG. 13  shows a longitudinal section through the center of the kayak  100 . Shown are the kayak  100 , the kayak seat  1300 , the angle oar  102 , the support post  118 , the bottom-mounted anchorage  1302  and a plurality of support post cavities  1304 . A plurality of support post adjustment holes  1500  are shown. The bottom-mounted anchorage  1302  is coupled to the kayak floor. The joint between the bottom-mounted anchorage  1302  and the kayak floor is sealed to prevent water from infiltrating the joint. The support post cavities  1304  are angled approximately 7° towards the kayak bow. The support system angle automatically angles the kayak paddle blades  106 ,  112  to provide some drag, advantageously keeping the blade  106  or  112  in the water during the stroke. 
     Referring next to  FIG. 14 , a detail of the longitudinal section of the bottom-mounted support  1302  is shown. Shown is the kayak  100 , the bottom-mounted anchorage  1302 , a plurality of support post cavities  1304 , the support post  118 , a bushing  1600 , a plurality of support post adjustment holes  1500 , a washer  1602  and an adjustment pin  1604 . The support post cavities  1304  are of tapered cone shape, with the narrower end at the bottom. In one embodiment of the invention, the cone is tapered to accommodate manufacturing requirements, with an approximate required angle of 2°-3°. The bushing  1600  sits on top of the support post cavities  1304 . Holes are located in the bushing  1600  to align the support post  118  in the support post cavity  1304  and prevent lateral movement of the support post  118 . In one embodiment of the invention, the support post  118  is supported by the bottom of the support post cavity  1304 . In another embodiment, the support post  118  and consequently the angle oar  102  may be raised by raising one of the support post adjustment holes  1500  above the top of the bottom-mounted anchorage  1302  and sliding the adjustment pin  1604  through the support post adjustment holes  1500  to secure the post. The washer  1602  is placed between the bushing  1600  and the adjustment pin  1604  to provide additional bearing support for the adjustment pin  1604 . 
     Referring next to  FIG. 15 , a detail of a transverse section through the bottom-mounted anchorage  1302  is shown. The kayak  100 , bottom-mounted anchorage  1302 , support post  118  and bushing  1600  are shown. In this embodiment, the support post  118  is shown supported by the bottom of the support post cavity  1304 . 
     Referring next to  FIG. 16 , another embodiment of angle oar anchorage is shown. The top-mounted anchorage  1800  includes an adjustable tube  1802 , a main support tube  1804 , a left support arm  1806  and a right support arm  1808 . Also shown is the kayak  100  and a portion of the angle oar  102 . A plurality of adjustable tube holes  1810  and an adjusting button  1812  are shown. The main support tube  1804  and the support arms  1806 ,  1808  are secured to the top of the kayak  100 . In one embodiment, a plurality of bolts  1814  connect the main support tube  1804  and the support arms to the top of the kayak  100 . The angle of the support arms  1806 ,  1808  provides rotational stability to the top-mounted anchorage  1800 . 
       FIG. 17  depicts a longitudinal cross-section through the top-mounted anchorage  1800 . Shown is the kayak  100 , the angle oar  102 , the support post  118 , a vertical support member  1900 , the adjustable tube  1802 , the main support tube  1804 , the left support arm  1806  and the right support arm  1808 . A plurality of vertical adjustment holes  1902  are shown on the vertical support member  1900 . The support post  118  is adjusted vertically by means of the vertical adjustment holes  1902  and a support pin  1904 . The vertical support member  1900  is coupled to the adjustable tube  1802 . In one embodiment, the angle between the vertical support tube member  1900  and the kayak floor is approximately 3°. The adjusting button  1812  is coupled to the adjusting spring so that the adjusting button  1812  extends through one of the adjustable tube holes  1810 , locking the angle oar  102  in place horizontally. An adjusting spring  1906  holds the adjusting button  1812  in place. To adjust the horizontal position of the angle oar  102 , the adjusting button  1812  is depressed until the adjusting button  1812  top is below the main support tube  1804 , allowing the adjustable tube  1802  to slide relative to the main support tube  1804 . The adjustable tube  1802  slides fore or aft until the adjusting button  1812  aligns with an alternate adjusting hole and the adjusting spring  1906  causes the adjusting button  1812  to extend through the alternate adjusting hole. The difference between the previous adjusting hole and the current adjusting hole is the change in angle oar  102  location. The plurality of bolts  1814  connecting the top-mounted anchorage  1800  to the kayak top are shown. A template may be supplied for locating the bolt holes in the top of the kayak. 
     Referring next to  FIG. 18 , one embodiment of the invention includes a stabilizing rod  2000  for a sit-on kayak. Shown is the kayak  100 , stabilizing rod  2000 , angle oar  102 , support post  118  and bottom-mounted anchorage  1302 . In one embodiment, the stabilizing rod  2000  is made of fiberglass or aluminum. The stabilizing rod  2000  has a tee handle. One or more through tubes  2002  are provided, allowing the stabilizing rod  2000  to pass through the kayak  100  without allowing water to enter the kayak  100 . 
       FIG. 19  depicts an isometric of the sit-on kayak  100  with the angle oar  102  and the stabilizing rod  2000 . Also shown are the kayak seat  1300 , the support post  118 , the top-mounted anchorage  1800  and the plurality of through tubes  2002 . 
     While the invention herein disclosed has been described by means of specific embodiments, examples and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.

Technology Classification (CPC): 1