Patent ID: 6439940
Filing Date: 2002-08-27
Classification: B63B

Abstract:
A fin and watercraft system, comprising:a watercraft, said watercraft having a front end, a rear end, a midpoint between said front end and said rear end, a lower surface, an upper surface, first and second sides and a centerline between said first and second sides; at least one pair of fins, said pair of fins comprising a first side fin and a second side fin, said pair of fins being disposed between the midpoint and the rear end, equidistant from said centerline and equidistant from said rear end; said first side fin being disposed adjacent said first side and said second side fin being disposed adjacent said second side; each of said first and second side fins having a top end, a bottom end, a leading edge, a trailing edge, a vertical axis, a horizontal axis extending from said leading edge to said trailing edge, a front portion extending from said leading edge to said vertical axis, a rear portion extending from said vertical axis to said trailing edge, and first and second lateral surfaces; each of said first and second side fins being rotatably mounted about said vertical axis to the lower surface of the watercraft; said first side fin being rotatable from a first position to a second position; said second side fin being rotatable from a third position to a fourth position; and whereby, when the watercraft is forced to move parallel to its centerline, an oncoming flow of water beneath the watercraft will cause the first side fin and the second side fin to rotate to the first and third positions, respectively, and when the watercraft is forced to move in a direction from the centerline toward its first side the oncoming water flow will cause the first side fin to rotate to the second position and the second side fin to remain in the third position, and when the watercraft is forced to move in a direction from the centerline toward its second side the oncoming water flow will cause the second side fin to rotate to the fourth position and the first side fin to remain in the first position.