Abstract: A method for providing a swim fin includes providing a foot attachment member and a blade member having a predetermined blade length. The blade member has a soft portion made with a relatively soft thermoplastic material. The method includes providing a relatively harder portion and the relatively soft thermoplastic portion that is molded to the relatively harder thermoplastic portion. The method includes providing an orthogonally spaced portion of the relatively harder portion that is arranged a predetermined orthogonal direction while said swim fin is in state of rest. The method includes providing the blade member with a predetermined biasing force portion that is arranged to urge the orthogonally spaced portion while the swim fin is in a state of rest. The method includes arranging a significant portion of the blade length to experience pivotal motion a lengthwise angle of attack during use.

Abstract: A method for providing a swim fin includes providing a foot attachment member and a blade member having a predetermined blade length. The blade member has a soft portion made with a relatively soft thermoplastic material. The method includes providing a relatively harder portion and the relatively soft thermoplastic portion that is molded to the relatively harder thermoplastic portion. The method includes providing an orthogonally spaced portion of the relatively harder portion that is arranged a predetermined orthogonal direction while said swim fin is in state of rest. The method includes providing the blade member with a predetermined biasing force portion that is arranged to urge the orthogonally spaced portion while the swim fin is in a state of rest. The method includes arranging a significant portion of the blade length to experience pivotal motion a lengthwise angle of attack during use.

Abstract: A method for providing a swim fin includes providing a foot attachment member and a blade member having a predetermined blade length. The blade member has a soft portion made with a relatively soft thermoplastic material. The method includes providing a relatively harder portion and the relatively soft thermoplastic portion that is molded to the relatively harder thermoplastic portion. The method includes providing an orthogonally spaced portion of the relatively harder portion that is arranged a predetermined orthogonal direction while said swim fin is in state of rest. The method includes providing the blade member with a predetermined biasing force portion that is arranged to urge the orthogonally spaced portion while the swim fin is in a state of rest. The method includes arranging a significant portion of the blade length to experience pivotal motion a lengthwise angle of attack during use.

Abstract: A method for providing a swim fin includes providing a foot attachment member and a blade member having a predetermined blade length. The blade member has a soft portion made with a relatively soft thermoplastic material. The method includes providing a relatively harder portion and the relatively soft thermoplastic portion that is molded to the relatively harder thermoplastic portion. The method includes providing an orthogonally spaced portion of the relatively harder portion that is arranged a predetermined orthogonal direction while said swim fin is in state of rest. The method includes providing the blade member with a predetermined biasing force portion that is arranged to urge the orthogonally spaced portion while the swim fin is in a state of rest. The method includes arranging a significant portion of the blade length to experience pivotal motion a lengthwise angle of attack during use.

Abstract: A method for providing a swim fin includes providing a foot attachment member and a blade member having a predetermined blade length. The blade member has a soft portion made with a relatively soft thermoplastic material. The method includes providing a relatively harder portion and the relatively soft thermoplastic portion that is molded to the relatively harder thermoplastic portion. The method includes providing an orthogonally spaced portion of the relatively harder portion that is arranged a predetermined orthogonal direction while said swim fin is in state of rest. The method includes providing the blade member with a predetermined biasing force portion that is arranged to urge the orthogonally spaced portion while the swim fin is in a state of rest. The method includes arranging a significant portion of the blade length to experience pivotal motion a lengthwise angle of attack during use.

Abstract: A method for providing a swim fin includes providing a foot attachment member and a blade member having a predetermined blade length. The blade member has a soft portion made with a relatively soft thermoplastic material. The method includes providing a relatively harder portion and the relatively soft thermoplastic portion that is molded to the relatively harder thermoplastic portion. The method includes providing an orthogonally spaced portion of the relatively harder portion that is arranged a predetermined orthogonal direction while said swim fin is in state of rest. The method includes providing the blade member with a predetermined biasing force portion that is arranged to urge the orthogonally spaced portion while the swim fin is in a state of rest. The method includes arranging a significant portion of the blade length to experience pivotal motion a lengthwise angle of attack during use.

Abstract: Methods are disclosed for improving the performance and design of snorkels (20) that are arranged to reduce splashes of water from entering the snorkel (20) during use. Methods including providing a non-floating active portion (72) and a spring member (54) to move active portion (72) to a closed position (68). Methods are provided for using weighted members (94) and, or floats (44) in conjunction with biasing members (54) exerted with torque across pivoting arms (42) and along longitudinal directions of motion (100). Methods are provided for enabling dry top snorkel devices (38) to automatically achieve, maintain or reestablish a closed position (68) at depth even if little or no pressure differential exists between the inside and outside of the snorkel (20) or if the sealed connection is disengaged at depth, such as can occur during a firm exhale at depth.

Abstract: A gas valve has housing and a barrier. The housing has a passageway with an upstream port and a downstream port. The barrier is disposed across the passageway and is formed from a material which is porous to compressed gas but which substantially prevents a low-pressure liquid from advancing through the passageway downstream of the barrier. The passageway may also contain a gas conditioner and/or a filter that is preferably disposed downstream of the barrier. In another embodiment, a valve comprises an inlet opening, a passageway extending downstream of the inlet opening, an attachment portion near the inlet opening, and a movable cap adapted to cover the inlet opening. The cap has a range of motion between a first position, wherein the cap covers the inlet opening, and a second position outside of the passageway, wherein the cap is displaced from the inlet opening. The cap is biased towards the first position. The gas valve may further comprise a gas regulator in fluid communication with the passageway.

Abstract: Methods are disclosed to design resilient hydrofoils (164) which are capable of having substantially similar large scale blade deflections under significantly varying loads. The methods permit the hydrofoil (164) to experience significantly large-scale deflections to a significantly reduced angle of attack under a relatively light load while avoiding excessive degrees of deflection under increased loading conditions. A predetermined compression range on the lee portion of said hydrofoil (164) permits the hydrofoil (164) to deflect to a predetermined reduced angle of attack with significantly low bending resistance.

Abstract: Methods are disclosed for designing improved flexible tubes and production methods which have improved flexibility and resistance to collapsing under load or during bending. Methods for injection molding a flexible tube (2) and providing at least one support member (4) that is arranged to provide improved lateral support to reduce lateral collapsing of the flexible tube (2). Methods for using and fabricating flexible tubes (2) are also provided for various shapes of support members (4) including annular ribs, helical ribs, spaced apart coils (128), narrow ribs, wide supports, as well as for various cross sectional shapes of flexible tubes (2), including streamlined elongated hydrofoil shaped cross sectional shapes relative to the longitudinal axis of flex tube (2).

Abstract: Designs and methods are disclosed for permitting scooped shape swim fin blades (184) to flex around a transverse axis to a significantly reduced angle of attack while reducing or preventing the scooped blade portion (254) from collapsing or buckling under the longitudinal compression forces (22) exerted on the scooped portion during a large scale blade deflection (212) by strategically alleviating or controlling such compression forces (222). Methods are also disclosed for increasing flow capacity, effective scoop length, scoop depth over a greater length of the blade, reducing blade resistance to large scale deflections, reducing bending resistance within scooped blade portions (254) that are experiencing high levels of blade deflection. Methods are also provided for reducing lost motion and increasing propulsion during the inversion phase of a reciprocating kicking stroke cycle while also increasing the formation of a scooped blade region (254) during the inversion phase of the stroke cycle.

Abstract: Methods are disclosed to design resilient hydrofoils (164) which are capable of having substantially similar large scale blade deflections under significantly varying loads. The methods permit the hydrofoil (164) to experience significantly large-scale deflections to a significantly reduced angle of attack under a relatively light load while avoiding excessive degrees of deflection under increased loading conditions. A predetermined compression range on the lee portion of said hydrofoil (164) permits the hydrofoil (164) to deflect to a predetermined reduced angle of attack with significantly low bending resistance.

Abstract: Methods for increasing the performance of a foil (100) by using tip droop (102) having an inward directed camber capable of generating an inward directed lifting force on the tip droop (102) in order to control spanwise flow conditions adjacent the tip (112) of a foil (100). Methods for varying the inward lifting shape of a tip droop (102) are provided along with methods for varying the angle of attack and camber of the tip droop (102) as the angle of attack of the foil (100) is changed and as spanwise flow conditions vary.

Abstract: Methods are disclosed to design resilient hydrofoils (164) which are capable of having substantially similar large scale blade deflections under significantly varying loads. The methods permit the hydrofoil (164) to experience significantly large-scale deflections to a significantly reduced angle of attack under a relatively light load while avoiding excessive degrees of deflection under increased loading conditions. A predetermined compression range on the lee portion of said hydrofoil (164) permits the hydrofoil (164) to deflect to a predetermined reduced angle of attack with significantly low bending resistance.

Abstract: Methods and designs are disclosed for providing a chin rest member (138) for reducing, distribution or alleviating loading forces (82) applied on a breathing device member (124) such as a snorkel (38), a second stage regulator (146) or other breathing devices using a mouthpiece (30) that is held inside the mouth of a swimmer. Methods for using a chin rest member (138) for reducing deformation of a mouthpiece (30), reducing jaw fatigue, reducing abrasion to the soft tissues of the mouth, improving air flow alignment, positioning and contouring of the mouthpiece (30) under the exertion of loading forces (82) are disclosed. Methods are also disclosed for adjusting the position the chin rest member (138) relative to the mouthpiece (30) as well as for accommodating different users having different size chins and, or overbite conditions, as well as methods for accommodating a major portion of majority of user's with one size.

Abstract: Methods are disclosed to design resilient hydrofoils (164) which are capable of having substantially similar large scale blade deflections under significantly varying loads. The methods permit the hydrofoil (164) to experience significantly large-scale deflections to a significantly reduced angle of attack under a relatively light load while avoiding excessive degrees of deflection under increased loading conditions. A predetermined compression range on the lee portion of said hydrofoil (164) permits the hydrofoil (164) to deflect to a predetermined reduced angle of attack with significantly low bending resistance.

Abstract: Methods for increasing the performance of a foil (100) by using tip droop (102) having an inward directed camber capable of generating an inward directed lifting force on the tip droop (102) in order to control spanwise flow conditions adjacent the tip (112) of a foil (100). Methods for varying the inward lifting shape of a tip droop (102) are provided along with methods for varying the angle of attack and camber of the tip droop (102) as the angle of attack of the foil (100) is changed and as spanwise flow conditions vary.

Abstract: Methods are disclosed for increasing lift and decreasing drag on hydrofoils and swim fins. The methods include providing a hydrofoil with a highly swept back leading edge portion and orienting the hydrofoil at a significantly reduced angle of attack in which the reduced angle of attack occurs at an angle that is substantially transverse to the hydrofoil's direction of movement through a surrounding fluid medium. The lee surfaces of the hydrofoil are provided with a substantially unobstructed flow path as well as a separation reducing contour so as to permit lift generating attached flow conditions to form along such lee surfaces. Substantially rigid structural reinforcement is provided to prevent the hydrofoil from deforming significantly during use. Methods are disclosed for providing a hydrofoil with a substantially longitudinal recess or venting system located substantially along the center axis of the hydrofoil.

Abstract: Methods are disclosed to design resilient hydrofoils (164) which are capable of having substantially similar large scale blade deflections under significantly varying loads. The methods permit the hydrofoil (164) to experience significantly large-scale deflections to a significantly reduced angle of attack under a relatively light load while avoiding excessive degrees of deflection under increased loading conditions. A predetermined compression range on the lee portion of said hydrofoil (164) permits the hydrofoil (164) to deflect to a predetermined reduced angle of attack with significantly low bending resistance.

Abstract: Methods are disclosed to design resilient hydrofoils (164) which are capable of having substantially similar large scale blade deflections under significantly varying loads. The methods permit the hydrofoil (164) to experience significantly large-scale deflections to a significantly reduced angle of attack under a relatively light load while avoiding excessive degrees of deflection under increased loading conditions. A predetermined compression range on the lee portion of said hydrofoil (164) permits the hydrofoil (164) to deflect to a predetermined reduced angle of attack with significantly low bending resistance.