Fin-driven water sports device

Abstract

The invention relates to a water sports device comprising at least one boat hull which carries the water sports participant and which is driven via special fins according to the invention. Via the inner restoring spring force of these fins, ducking and swinging movements are triggered by the runner rolling forwards and backwards on guide rails in the manner of cross-country skiing, which ducking and swinging movements lead synchronously to propulsive fin flapping. The possibility opened up here of moving freely thereover in an upright position in a running or dancing manner is safeguarded by hand connection on both sides to cross-country ski poles via buoyant pole baskets with respect to the water surface, and the force-fitting integration of the poles in rowlocks on a movement-guiding boom which is co-rotatingly anchored behind the person on a column on the boat hull. The sensitive connection with the softness of the water opens up the entire body, all the way from fingertips to toe tips, to delightful self-awareness and the chance of reducing internal tension.

Description

[0001] 12 / 01 / 2025 PCT / DE2025 / 000110 Oa-12-2025“©023357B-O i

[0002] Günther Pohlus, Dennig 3, 96317 Kronach, Tel. 09261950433, mail: pohgue@t-online.de 003

[0003] Kronach, October 29, 2025 (Updated as of October 28, 2025 following corrections to examinations carried out by the German Patent and Trade Mark Office Munich under file number 102024003562.1, of the patent application dated October 31, 2024)

[0004] International PCT patent application

[0005] Fin-powered water sports equipment:

[0006]

[0001] The invention relates to a water sports device with at least one elongated hull which mainly supports the water sports enthusiast, the propulsion of which is provided by special fins, the internal elasticity of which triggers ducking and rocking movements by cross-country skiing-like forward and backward rolling of the athlete on guide rails provided for this purpose, which thus lead to propulsive fin beating.

[0007]

[0002] Currently known manually operated water sports equipment, which, like the water sports equipment according to the invention described here, is moved in an upright body position, uses, as far as is known, either a stand-up paddle, a pole for poling, a rudder lever or is dependent on "standing waves" to gain speed.

[0008]

[0003] Furthermore, according to officially determined prior art, as per documents D1-D3, inventions have been identified that allow cross-country skiing-like propulsion on the water surface. However, the depictions in question all utilize rigid rudder surfaces that can be folded up and down as a propulsion element in the current, but these have proven to be obsolete, for example in paddle steamers, compared to the ship's propeller.

[0009] The comparison is explained physically by the fact that one must not break the resistance of water (its inertia) if one wants to use it for ever faster propulsion, but rather, as the speed increases, the water must be offered a suitable angle of encounter with a propulsive surface to allow it to flow away. This is precisely what ship propellers, fish fins, and, as described below according to the invention, offer.

[0010] CONFIRMATION COPY 01.12.2025 PCT / DE2025 / 000110

[0011] described drivers, which can be called "device fins".

[0012]

[0004] In contrast to previously published inventions, the invention is based on the objective of ensuring forward progress by means of a continuous forward and backward rolling / gliding motion almost identical to cross-country skiing, which takes place either on both sides of a supporting boat hull or between and on two boat hulls with roller connections over a central transverse axis on longitudinally mounted hydrofoils on guide rails and there causes an alternating up and down movement of the fin heads rigidly mounted below the water surface between the bow and stern directions, the restoring force inherent in these fin heads and the articulated fin flanks triggers the beating or waving of "fluidly springy" fin surfaces, which not only provides propulsion and lateral stability, but ideally enables balance stability and a kind of "wave-riding surfing" by constantly "riding" on a continuously self-generated wave.

[0013]

[0005] A simple alternative, by means of variable locking of the two hydrofoils of the guide rails which can tilt in opposite directions in cross-country mode, consists of eliminating this independence of the port and starboard hydrofoils in the ducking position by coupling them to the main axis connecting them, which is anchored in the boat hull, for example by means of ball locking pins or clamping levers. Such synchronization of the two hydrofoils in their parallel tilting and raising capability necessitates and simultaneously enables a movement and force application on the device that differs from cross-country skiing, because, similar to the rocking gait on a tilting beam, it requires a significant weight shift not only in the direction between bow and stern, but also between port and starboard.In terms of movement, this is more akin to cycling up a steep hill, where the cyclist lifts off the saddle and, standing on the pedals, shifts their weight alternately onto each pedal. This affects not only the movement pattern but also the rhythm, as each step involves a diagonal movement across the torso, whereas with independent tilting of the support rails, this movement occurs symmetrically along the longitudinal axis and thus simultaneously on both sides of the boat's hull.

[0014]

[0006] An additional interesting aspect of the more cycling-like variant is that the active user has the option of switching sides after each diagonal movement while rolling with leg spread, which for a moment resembles cross-country skiing. 01.12.2025 PCT / DE2025 / 000110

[0015]

[0016] .01" 12^2025-00238573-0013

[0017] would correspond, however, to its rather "self-contained" dynamic.

[0018] Apart from the aforementioned and uncomplicated manual adjustment using locking bolts or clamping levers, the described alternative requires no additional effort when used only temporarily.

[0019] A technical intervention that alters the device or the entire system. Long-term use.

[0020] However, this would likely only be possible with an adaptable differentiation of fin characteristics and

[0021] whose arrangement within the system makes sustainable sense.

[0022]

[0007] A design that can be realized with only one supporting boat hull is, preferably

[0023] in front of or behind the crouching wings on both sides, with additional fins both laterally and

[0024] also available on the bow or stern, the activation of which is hardly achieved by ducking the central hull, but rather by its lateral rocking, which results from the not entirely unavoidable shift of the "water cross-country skier's" body weight between the left and

[0025] to the right of the central hull_results.

[0026]

[0008] In addition to the centrally transversely mounted tilting axis,

[0027] (whose functionally determined position is not necessarily precisely in the middle of the metric length of the

[0028] (which must lie on the boat's hull, but depends on interacting factors).

[0029] for the lateral support surfaces of the guide rails and their fins articulated below them,

[0030] Additional floats, which move along both sides and provide additional lateral stability, can increase the track width and capsize resistance via a further common transverse axis, preferably positioned slightly forwards, whereby they can move either individually or via the common axis.

[0031] together, they can adjust to a wavy water surface. This arrangement would correspond to

[0032] For example, common Trymaran versions. With adjustable spacing of such laterally and lockably movable additional floats, these form a platform as needed, which can be used for resting.

[0033] It can be used while lying down or sitting.

[0034]

[0009] If, instead, a catamaran-like design of load-bearing twin hulls is used, then

[0035] the guide rails on their tilting support surfaces both between and within or

[0036] These two hulls are rigidly connected across their common transverse axis, ensuring that the lateral distance between the feet and legs corresponds to the anatomical requirements of cross-country skiing, and that the shape, length, and width of the hulls supporting the transverse axis guarantee gliding with minimal ducking and resistance, and that their overall width allows for free swinging of the cross-country ski poles and swimming alongside the skis.

[0037] the cross-country ski pole basket is not restricted. 01.12.2025 PCT / DE2025 / 000110 01-12-2025-00233573-0014

[0038]

[0010] In the context of the invention, it should further be noted that in both monohull and catamaran arrangements of the supporting boat hulls, the hydrofoils and guide rails with the downwardly projecting fin attachment rods must be provided with extensive separation from the oncoming flowing water, preferably by providing separate, as close-fitting as possible shields, which also prevent the bobbing hydrofoils from acting as a brake against the watercourse.

[0039]

[0011] Commercially available swim fins integrate organically with the swimmer's foot through the smooth connection with the swimmer's foot, incorporating the interaction of the swimmer's extensive physical muscle exertion into the fin's inherent elasticity, from the heel to its ever-softening fin surface, which extends far beyond the toes.

[0040] In contrast, the design of the fins producible according to the invention is characterized by the fact that their fin head axis, to which the elastically waving fin surface is connected, follows its movement with its internally rigid core solely along the rigid connection – perpendicular to the fin surface – to the wing and guide rail ends. Thus, during vertical up- and down-diving, the fin surface is connected to this core in its innermost position only tangentially – simultaneously rigidly and resiliently. It is only through this connection that the fin surface acquires its outwardly extending elasticity and restoring force.

[0041]

[0012] The property of the fin according to the invention is easier to explain and can be produced alternatively if its mostly horizontal fin head axis, which is comparable in rigidity to the horizontally, transversely and stiffly arranged bicycle pedal axis, is first equipped with a spring that stores the return angle and the spring force. This spring is firmly anchored towards the core and transfers its spring tension, charged by ducking, outwards to a sleeve rotatably mounted on it. The elastic fin body is firmly attached all around to the tubular outer wall of this sleeve, thus absorbing the energy stored in the spring via the sleeve. Another quality and property of the fins according to the invention and their waving surface consists in having a surface structure similar to that of bony and cartilaginous fish, in order to transmit static and dynamic forces to the fin tips and to suppress inhibiting turbulence.

[0042]

[0013] To further facilitate the challenging balancing of the presented water sports equipment for the cross-country skier, the invention provides that the horizontal axes of the crouching 01.12.2025 PCT / DE2025 / 000110

[0043] The fin heads, and therefore also their fin surfaces, should be angled slightly sideways outwards and upwards by a few degrees to minimize the risk of lateral "slipping" with the fins positioned completely horizontally.

[0044]

[0014] A further stabilizing measure according to the invention consists in giving the shape of the fin head and its subsequent transition into the fin flank a lift-generating frontal profile, as is used, for example, in aerodynamically and lift-promoting ways in wings and airfoils, whereby - in order to minimize friction losses - the slenderness of the fin head front is of equal importance.

[0045]

[0015] As in cross-country skiing, rhythmic running is hardly possible without the counter-swing and propulsion provided by the arms. As in cross-country skiing, the use of poles for propulsion and supporting rhythm and balance is essential in the "water cross-country skiing" method according to the invention. While on the track both snow and the surface provide a relatively firm base for pushing off and supporting oneself, water offers such firmness only through its surface cohesive properties, which means that preferably parallel contact surfaces exhibit particularly strong resistance to one another.

[0046]

[0016] In the embodiment of the invention, these "water cross-country ski poles" utilize their "pole basket," which automatically adjusts to the respective water surface and has a pivotally free-tracking, downward-pointing release flap. The release surface, which allows for freedom of movement and is suspended from a transverse hinge, utilizes the "pulling" motion of the poles that predominates in any cross-country skiing. This allows the downward-pointing release flap to trail freely and with minimal resistance in the open position until the moment of push-off. At this point, the flap strikes the stopper on the laterally flanking "basket fins" and, via their preset angle of attack, can capture a full and frontal volume of water.

[0047]

[0017] The two fins, which serve as the primary guides for the pole baskets, control the course of the basket with their limiting wall surfaces, which are perpendicular to the hinge axis. They cut through the water with minimal resistance during the pull-back stroke and with razor-sharp precision during the push-off stroke, ultimately finding support and guidance in the handle of the pole. To prevent the supporting pole baskets from tilting or flipping over, for example in choppy water, their horizontal tilting range is precisely controlled laterally by the pole foot hinge and longitudinally by an appropriate limitation of their free angle of movement. 01.12.2025 PCT / DE2025 / 000110

[0048] 6

[0049]

[0018] In an embodiment for experienced "water runners", the use or extension of laterally parallel support fins can be dispensed with if the dimensions of the fins, their area, their stiffness and elasticity, and their distance to each other in relation to the wave sequences that can be generated, have been coordinated in such a way that a continuous wave sequence can be built up and maintained by the athlete in a powerful rhythmic repetition of the up and down push-off motion, so that running becomes continuous wave surfing and, similarly to cycling, provides lateral stability increasingly as speed is gained.

[0050]

[0019] Learning this "wave surfing on fins" and even practicing it for those skilled in it would be hardly conceivable without the necessary means, provided by the invention, of maintaining the difficult balance – standing and walking freely above the water. Similar to the delicate conditions in a racing skiff, this is achieved according to the invention by connecting the two water cross-country ski poles approximately in the middle of their shafts behind the skier's body by means of a rigid T-shaped rod connection via articulated joints (dowel-like) on both sides, in order to connect them there as a centrally vertical and rigid "T" column, yet rotatable, to a base rigidly anchored in the boat hull.

[0051]

[0020] To ensure that the poles are connected at all times between the cross-country skier's hands and the buoyant floats on the water's surface, forming a three-column pyramid that provides a firm hold and orientation, another essential connecting element is required. This is achieved by attaching the poles via the oarlocks located on the outer sides of the horizontal central strut. The pole handles are equipped with stop rings before passing through the oarlocks and are in constant, firm contact with the T-shaped intermediate column by the cross-country skier continuously pressing the pole ends against them with their thumbs or handles.

[0052]

[0021] In addition to the two moving “stick columns” leading at a very steep angle to the water, the athlete’s body thus becomes the third column, in that the stick-handling hands, as it were at the top of the pyramid, retain both support and the necessary freedom to react in opposition to waves and imbalances.

[0053]

[0022] The design and connection of the components on the side support surfaces and guide rails 01.12.2025 PCT / DE2025 / 000110 Bl'“Il-Ä025^Q a33573“OQ17

[0054] Forward and backward movable roller connections are preferably possible with market-like click pedal connections in order to ensure, in addition to the maximum possible movement of the toes and heels while walking, a quick escape before and during any capsizing.

[0055]

[0023] In order to ensure that the reversal of movement at the ends of the rails occurs smoothly and without abrupt collisions, the design according to the invention provides a rounded shape on the wings and guide rails, either entirely or only at their ends, so that each rollback is initiated in a sensitive and perceptible manner. Another option for a gently assisted reversal of movement and step is a braking mechanism that can be set at the ends of the rails by means of stop springs, which is also capable of generating momentum from the reversal. To prevent excessive vertical tilting of the support rails forward and aft, their deviation from the main fuselage is limited by spring-loaded stops or by return springs in the transverse axis.

[0056]

[0024] While fish actuate their fins directly by muscular or antagonistic action, the propulsive and deflection force in the fin design according to the invention is ensured by the fact that the shape, structure, and technology of the artificially produced fins for cross-country swimming are designed such that their mode of propulsion generation is achieved on the one hand by external (perpendicular) movement initiation and on the other hand by internal storage of recoil force. While commercially available swimming fins are mostly made of rubber, neoprene, or plastic, for an inventive design, for example, thin spring sheets layered in graduated increments or correspondingly bonded or welded plastic layers or corresponding composite materials, for example, with the use of textile or carbon fibers, are also suitable.

[0057]

[0025] The intended "elongated stranded" structuring of the fin surfaces not only serves the internal statics, but also has the function of limiting the lateral escape of the water displaced during ducking and fanning.

[0058]

[0026] Anyone planning to market water sports equipment suitable for recreational use today would be well advised to consider the multifaceted requirements, interests, and vulnerabilities in nature and society. In this respect, there is initially little to prevent the use of the invention on a wide variety of inland waters. However, anyone who draws on experience and 01.12.2025 PCT / DE09^fiß11O 01 -I2-202S“00233£7«Üll

[0059] Looking at the development of windsurfing, for example, one can see that natural spaces are limited and endangered on the one hand, while "modern man" is all the more urgently seeking and needing open spaces and recreational areas than, for example, a dwindling and endangered skiing area can offer in the long term and sustainably.

[0060]

[0027] Taking this into account, the present development includes offering facilities for training and practice opportunities in the immediate vicinity of the place of residence and all year round, especially in metropolitan areas without proximity to lakes, rivers or suitable canals, within the framework of "water cross-country ski trails" that can be laid out in a variety of ways.

[0061]

[0028] In the following, exemplary embodiments of the invention are explained with reference to the drawing:

[0062] They show:

[0063] Fig. 1: A top view of a water sports device operable with fins in

[0064] single-hull design.

[0065] Fig. 2; A side view of Fig. 1 in section A / B, (also applicable to Fig. 4).

[0066] Fig. 3: A front view of Fig. 1 in section C / D

[0067] Fig. 4: A top view of the water sports equipment in "catamaran version"

[0068] Fig. 5: A front view of Fig. 4 perpendicular to the transverse axis QZ in section E / F

[0069] Fig. 6: A top view of the plate of a water cross-country ski push and

[0070] Balance sticks

[0071] Fig. 7: Side view of Fig. 6 in section A / B

[0072] Fig. 8: A perspective sketch of a figure in action

[0073] Fig. 9: Example of an artificial water cross-country ski track for training, practice and recreational use

[0074] Fig. 10: Side view of Fig. 9 in section A / B

[0075]

[0029] According to Fig. 1,

[0076] The invention comprises a water cross-country skiing device comprising a central boat hull (1) and two hydrofoils (2) that are capable of being tucked forward and aft about the largely central and common transverse axis (6). The hydrofoils are equipped with guide rails (3a, 3b) in their respective opposing configurations on the port and starboard sides. Adapted roller attachments (3c), preferably for loose click-in and click-out, are provided on these hydrofoils. 01.12.2025 PCT / DE2025 / 000110

[0077] 01-12-2025-00233573-0019

[0078]

[0030] The fins (4, 4.1), which are articulated to propel the boat forwards and backwards by means of a rigid linkage (4b) below the water surface, are articulated forwards with their fin head (4a) in front of and beside the hydrofoils (2) and backwards directly adjacent to them (2), and all extend sufficiently deep below the water surface (WO), while the keel, side and tail fins (5, 5.1, 5.2) attached to the central hull (1) do not propel the boat by crouching but, if necessary, by side rocking.

[0079]

[0031] Airfoils (2) with guide rails (3a and 3b) are attached axially (6.1) to the axle tube (6) which preferably extends telescopically through the transverse axis (QZ) and are designed to be freely rotatable (over or in each other) between the port and starboard sides and can be coupled to each other by means of locking bolts (6.2), which then synchronizes the movement of the airfoils.

[0080]

[0032] To limit excessive forward and aft deflection of the hydrofoils (2) with pedal carriages (3c), spring-loaded limit stops (10) are provided between the boat hull (1) and the hydrofoils (2), unless this function is already performed by axially arranged return springs. The illustration also shows the possibility of protecting the roller attachments (3c) from spray by hydrodynamically curved mudguards (11).

[0081] [0331 According to Fig. 2,

[0082] Fig. 1 shows a side view, from view A / B, of the starboard wing (2) with guide rail (3a) and rolling or sliding roller attachments (3c) on it. It is shown here in the foreground in front of the main fuselage (1), and the marking of the stop angle (r / 3a-3b) shows that it is just touching the upper deflection limit (10).

[0083] In the free arrangement of the wings (2) above the water, the attachment of a splash guard (11) (a kind of mudguard) is also indicated here.

[0084]

[0034] Additional side fins (5.1) are located, provided the boat hull (1) is sufficiently long, exclusively on and preferably at a distance in front of or behind the hydrofoil fins (4). Keel fins (5) are presumably only used if the navigable water provides sufficient draft and if the absence of the support floats (7) by experienced cross-country paddlers can produce a correspondingly strong rocking motion. 01.12.2025 PCT / DE2025 / 000110 01-12-2025-00233573-0020

[0085]

[0035] According to Fig. 3,

[0086] The side view in section C / D on Fig. 1 includes the front view according to the invention from the plane of the water surface (WO) perpendicular to the transverse axis (QZ) of the single-hull version.

[0087] The design differs in the arrangement of the free-running hydrofoils (2) above the water (compared to the catamaran design), by having only one hull (1) and thus places higher demands on the ability to balance.

[0088]

[0036] According to Fig. 4.

[0089] The figure includes a top view of the model shown here as a "catamaran version" according to the invention, consisting of two supporting hulls (1) connected to each other by a common, preferably rigid, transverse axis (6). The axis or bearings (6.1) for independently hinged, tiltable wings (2) are arranged either inside or outside this axis and can be tilted. The fins (4, 4.1) are articulated to the wings via rigid linkages (4b) extending below the water surface. (In Figures 2-4, the associated "water cross-country ski poles" are only indicated due to space constraints.)

[0090]

[0037] According to Fig. 5,

[0091] Section E / F, viewed from the water surface (WO), shows that the guide rails (3a, 3b) supporting the hydrofoils (2) are located in the catamaran version either, as shown in Section E / F, inside or on the deck of the hulls, or (not shown) between them. Furthermore, it is visible that although the guide rails (3a, 3b) supporting the hydrofoils (2) are supported by the hulls (1) via the central axis (6), their deflection occurs independently via the normally independently rotating telescopic tubes (6.1) without any significant deflection effect on the hulls (1).

[0092]

[0038] According to Fig. 6,

[0093] includes a top view of the stock plate (13) according to the invention.

[0094] The stick (15) is hinged to the surface of the plate (13) approximately perpendicular to the direction of travel (F) via a hinge (16), allowing the hands (H) holding the sticks to sensitively feel and maintain their grip on the connection to the water. As the two required sticks (15) are pulled along in the direction of travel (F), a bulge (17) projecting below the water surface (WO) forms, leading and trailing the plate (13). At the front, this bulge resembles the head of a fish swimming at the surface, hence the 01.12.2025 PCT / DE2025 / 000110

[0095] The frontal periphery may have slightly more volume to provide more lift than the wake (17.1).

[0096]

[0039] According to Fig. 7,

[0097] includes a side view shown in cross-section A / B in Fig. 6.

[0098] In floating operation, a cohesive, planar air layer (18) forms in the buoyant plane between the water surface (WO) and the base of the stick plate (19), ensuring particularly low-resistance gliding of the stick plates (13) during operation. According to the invention, it is advantageous if the air and water flows are directed downwards in the center (19.1) by a slight downward curvature of the base of the stick plate (19), thus distributing and dissipating the air and water flows somewhat.

[0099]

[0040] A slightly upwardly curved outer surface (20) of the stick plate (13) allows the splash water to run off in all directions, sloping outwards from the center of the stick plate. In the stick foot area (16), the angle of play (21) is also determined by suitable stop limits, which allows the stick plate (13) to adjust itself appropriately to the stick (15) and the water (WO) in response to smaller waves crossing in the direction of travel, while simultaneously preventing the stick plate (13) from flipping over or dipping.

[0100]

[0041] It should be noted that the plate surface is advantageously made of rigid plastic and, alternatively, a domed lid (20), preferably either hollow or made of lightweight and stiffening foam, can be superimposed on it, with sufficiently stable anchor surfaces being provided for the connection of the stock shackle (16) and the downward-projecting fins (22).

[0101]

[0042] If a cover (20) is provided, the gap opening above the lid bottom (19.1) in the angle (21) can be sealed watertight by a cuff (33), for example made of rubber.

[0102]

[0043] Primarily steered in the direction of travel (F), the pole baskets (13) are controlled via the poles (15) in the hands (H), both during the pull-up and the push-off phase, by the knife-like downward-cutting fins (22). At a right angle to this, and freely trailing when idling, the side walls of the fins (22) are folded upwards (24.2), by the so-called push-off flap (23) in between, which is closed during the push-off phase against the direction of travel (FR) and at 01.12.2025 PCT / DE2025 / 000110

[0103] '01-12^2025-00233573-13022

[0104] following the pulling of the stick (15) by the flow of traffic so that its hinge (24.1) located on the upper edges of the fins opens again

[0105]

[0044] According to Fig. 8,

[0106] Figure 1 shows the integration of the poles (15) in the hands (H) of a "fin surfing" person (P) within the overall system described. To ensure sufficient safety and stability at all times during use of the water sports device according to the invention, the person (P) would not be able to safely push off and brace themselves against the water surface (WO) using only the poles (15) via the pole baskets (13) without an additional connection. This connection is provided by a horizontally rigid linkage (25) located centrally (25.1) between the poles (15), rigidly but rotatably, via a rigid pillar (26) that is fixed and vertically anchored behind the person (P) at (27) in the boat hull (1). Alternatively, as is possible in a catamaran version, it can be connected to a rigid linkage between the hulls (1).

[0107]

[0045] This pole-handle linkage between the hands (H) of the person (P) and the floating pole baskets (13) finds its ultimate support only in the fact that the gap of the joint connection to be closed there between the pole handles (15) and the horizontal connecting strut (25) is closed by means of rotatable oarlocks (28) attached to the strut ends, on the ring-shaped opening of which the pole handle rings (29) which are seated at the correct height on the poles (15) find a stop SX' and hold by constant light thumb pressure on the handle grip (H), so that the person (P) exercises the given movement 1*ung Uskop ft p - lung S» between the left and right pole, to put the levers in the hand, to maintain their balance without interruption and to control.

[0108] Lateral stability is ensured even when using the handles (H) thanks to a simple, temporarily fixable connection. A seat (not shown) can also be attached to the pole connection (30) above the column (26) for rest periods.

[0109]

[0046] During the cross-country skiing motion of the pole-handling arms and hands in opposite directions, the linkage connection (25), due to its horizontal rotation centrally on its pillar (26), causes the pole handles (15) and pole baskets (13) to move away from each other in a non-parallel manner, due to its cyclical, increasing or decreasing rotation. This can lead to problems, especially when the person (P) moves their hands or arms particularly close to their body. 01.12.2025 PCT / DE2025 / 000110

[0110] The exercises involved increasing the spread of the poles (15) and slightly moving the pole baskets (13) apart or closer together. This also demonstrates how, despite shifting reference points in the overall system of body (P), boat hull (1) and water surface (WO), the water sports enthusiast maintains secure balance at all times.

[0111]

[0047] A turn or cornering maneuver is preferably initiated by extending the cross-country ski poles (15) connected to the frame (25) laterally up to 4-5° opposite the direction in which the course change is to be made. In this case, both fin plates (22) are positioned largely perpendicular to the direction of travel and, like a lateral rudder, provide one-sided braking for the course change around the fins (22).

[0112]

[0048] For alternative turning and steering, the use of manual remote control via an additional stern steering system (12) is also possible. The length dimensions and distance relationships to be optimized for the poles (15) and the linkage levers (25 and 26) must be determined and taken into account according to the individual requirements and in relation to each other.

[0113]

[0049] According to Fig. 9,

[0114] The sketch shows the construction of an artificial water cross-country ski track (L) as a facility for training, practice, and recreational use in a section perpendicular to the transverse axis (QZ): The artificial enclosure of the water by barriers (31) is depicted, which can be constructed, for example, of concrete, wood, or composite materials. The sole and centrally guided boat hull (1) supports the central axis (6) running above it, on which the articulated hydrofoils (2) with roller attachments (3c) are mounted on guide rails (3a, 3b) on both sides of the guide channel (32). The fin-guiding rods (4b) are articulated to the hydrofoils (3a, 3b), which project rigidly and stiffly below the water's surface. These rods terminate in the fin heads (4a), which transmit their inherent restoring force to the fin surfaces (4). The cross-country ski poles (15) are only indicated here.

[0115]

[0050] According to Fig. 10,

[0116] In this figure, a side view of the artificial "water cross-country ski trail" according to the invention is shown, as shown in section A / B in Fig. 9.

[0117] The boat hull (1), moving in the direction of travel (F), automatically centers itself almost frictionlessly between the walls (31) of the guide channel (32), which is temporarily and provisionally - approximately until 01.12.2025 PCT / DE2025 / 000110

[0118] ©1-12-2025-00233573-0024

[0119] For training and educational purposes, the facility may also be constructed in a natural body of standing or flowing water, whereby artificial channeling outside the central guide channel (32) may be omitted. Such training and educational facilities could be designed to be space-saving, horizontally curved, and approximately closed-circle. 01.12.2025 PCT / DE2025 / 000110

[0120] - 12”2Ö25~O0233573^OO25

[0121] [0511 List of symbols used in the drawings:

[0122] 1: Boat hull,

[0123] 2: Wing,

[0124] 3a, 3b: Guide rails assigned to port and starboard

[0125] 3c: Roller connections

[0126] 4a: Fin head

[0127] 4b: Rigid linkage of the fins

[0128] 4, 4.1: Fins

[0129] QZ: Central transverse axis

[0130] WHERE: Water surface

[0131] 5, 5.1, 5.2: Keel, side and tail fins

[0132] 6: Continuous axis

[0133] 6.1: Axial attachment of the wing

[0134] 6.2: Here, coupling of 6 and 6.1 by locking bolts

[0135] 7: Additional swimmer

[0136] 10: Outward deflection stops between wing (2) and hull (1) 11: Shielding against spray and flowing water

[0137] 12: Alternative conventional rear steering

[0138] 13: Stock plate

[0139] 15: Stock

[0140] 16: Hinge between cane foot and cane plate

[0141] 17: Front ridge of the stock plate

[0142] 17.1 Rear bulge of the stock plate

[0143] 18: Air layer

[0144] 19: Stock plate bottom

[0145] 19.1 Underside curvature in the stock plate

[0146] 20: Stock plate lid

[0147] 21: Gap angle in the stock plate lid

[0148] 22: Finns

[0149] 23: Locking flap

[0150] 24: Stop of the locking flap

[0151] 24.1: Locking flap in closed position

[0152] 24.2: open locking flap

[0153] FR: against the direction of travel

[0154] 25: horizontal linkage

[0155] 25.1: ditto. their pivot point

[0156] 26: Rod pillar

[0157] 27: Pillar base anchoring in the boat hull or, in the case of catamarans, in between.

[0158] 28: Dollies at the ends of the horizontal frame

[0159] 29: Stock stem ringing

[0160] 30: Linkage pivot point

[0161] 31: Water barriers

[0162] 32: Central guide channel of the water cross-country ski trail

[0163] 33: Cuff

Claims

CHANGED REQUIREMENTS Received at the International Bureau on 12 June 2026 (12.06.2026) 1. Water sports equipment with at least one elongated hull (1) capable of supporting a water sports enthusiast (P) sufficiently above the water surface, with a central transverse axis (QZ) and hydrofoils (2) mounted on it in a tiltable manner on the port and starboard sides, respectively, with longitudinally extending roller tracks on guide rails (3a, 3b) for a counter-rotating, cross-country-style forward and backward rolling motion guided above them on roller connections (3c), which, preferably running below deck or close to the water (WO), exerts a ducking of the hydrofoil (2) onto a fin head (4a), characterized in that, that the wings (2) are mounted above the central transverse axis (QZ) and are capable of tilting on it, At the bow and stern of the wings (2) via a rigid linkage (4b) extending below the water surface, swim fins (4, 4.1) of a special design are articulated such that their fin head (4a) is tangentially rotationally fixed to the respective linkage ends (4b) and thus stores restoring force in itself and via its connected fin surfaces (4, 4.1) both in the up and down movement and cyclically discharges it, thus generating propulsion in the triggered up and down movement of the fin surface relative to the water.

2. Water sports equipment according to claim I, characterized by that by synchronizing the normally independently tiltable and flexible wings (2) on the central transverse axis (6) rigidly mounted in the fuselage, for example by means of connecting ball locking pins (6.2), a quick and uncomplicated switch from a cross-country skiing-compatible movement style to a more cycling-like body use is possible and can be done quickly and manually to undo 22.

3. Water sports equipment according to claim 1, characterized by that additional propulsion and lateral stability are made possible by the use of water cross-country ski poles (15), which can be supported or pushed off against the water (WO) via their pole baskets (13) and whose buoyancy-effective bulge (17) traps an air layer (18) allowing them to glide with low resistance and simultaneously be buoyant and drawn in by the water (WO), in the cycle of pushing off and pulling back, the poles (15) are to be used and which, by means of two fins (22) projecting vertically downwards at the bottom of the pole basket (19) parallel to each other, keep the pole basket (13) in a sharp direction, allow it to be steered forwards and backwards and provide push-off retention by means of a hinge (24) on their upper edges in the front area.1) to support a freely and obliquely open closing flap (23) in the trailing current with minimal resistance, which immediately hermetically seals the space between the fins (22) to the rear as soon as and as long as the sticks (15) thrust in the direction (FR) and press and hold the closing flap (23) against stops (24).

4. Water sports equipment according to claims 1 to 3, characterized by that the cross-country skier (P), moving standing or across the water on a narrow boat hull (1), which should only slightly exceed the width of a medium-sized cross-country ski track in the snow, can only find secure footing because the two cross-country ski poles (15) in his hands (H) adhere reasonably reliably to the surface of the water (WO) via their pole baskets (13), either trailing or pushing off. The freely steering hands (11) can ultimately only find support and secure balance by connecting the two poles (15) behind the cross-country skier (P) at approximately their upper third via a rigid strut (25) and oarlocks (28) on both sides of it, and by attaching this strut (25) horizontally and rotatably in its middle (25.1) to a column (26) rigidly anchored vertically to the hull (1) at point (27), and by resisting the opposing pulling or pushing of the poles (15) with the central joint (25).1) can follow in a rotating motion, whereby the sticks (15) with their stick plates (13) are cyclically spread apart and brought closer together again, with the triple connection thus created between the hands (H) as the controlling apex of three pyramidally connected columns, which are supported twice over the sticks (15) on their stick plates (13) and find their third column base in the common anchoring point of the column (26) opposite the boat hull (1) at (27), whereby the reference plane for the balancing support on the water (H) is established at any time and can be felt and controlled. The horizontal stick connection (25) can be used to meet the requirements of increased lateral stability and safer 23 AMENDED SHEET (ARTICLE 19) Maneuverability on both sides of its column connection (25.1) to the column (26) extendable - for example by exchange - in order to effect a particularly wide spread of the stick plates (13) while maintaining a narrow stick guide in the hands (H) of the person (P).

5. Water sports equipment according to claims 1-4, characterized by that the water sports device according to the invention can be steered for the purpose of changing course or returning to the starting point by the fact that, similar to the effect of normal stern steering, the change in the straight-ahead course is achieved by the boat hull (1) being shifted significantly more laterally instead of forwards in its longitudinal direction. According to the invention, this is accomplished by the steering person (P) pivoting one of the two poles (15) with a paddle (13) behind their back on the rotating central strut (25) with the rotating column (26), pivoting it until it is at its maximum extent over the separating boat hull, and then lowering it on the same side of the hull (1) of the other pole (15), so that, through continued finning due to the transverse and braking resistance of the fins (22) of the two poles (15), the boat hull (1) is steered in this direction, and a subsequent straight-ahead course is achieved by completing this turning procedure.This steering process can be carried out without significantly impairing the stability of the person (P), because even when one of the stick handles (15) is swung behind the back of the person steering (P), balance is maintained, as the person (P) can maintain stability at this moment by consciously shifting their weight from the held second stick handle (H) to its handle plate (13) via the column base connection (27) to the water (WO). Not only here, but also for use on a straight course, the invention provides that the sticks (15) can be temporarily extended towards their handle ends, for example by pressing a button (e.g., telescopically), so that the handle ends (FI) can be brought together and held in a triangle during a turn or rest phase, either manually or by a simple mechanism, thus leaving both hands (H) free for the person (P). 6 Water sports equipment according to claim 1 and 2, characterized by by the cross-country skiing-like and cyclical alternation of the respective opposite forward and backward movement not only of arm and leg swing, but primarily by the diagonally opposite change of direction in the left and right step preferably via rail-guided rolling over a central transverse axis (QZ), wherein the connection to the wing surfaces (2) thereby caused to duck is ensured by the fact that the feet of the person (P) are connected in a rolling or sliding manner to rail-guided (3a, 3b) roller connections (3c) which the 24 AMENDED SHEET (ARTICLE 19) resemble clipless pedals in road cycling and immediately release the feet of the "water cross-country skier" in the event of an impending capsize and, when re-mounting onto the torso, enable uncomplicated reconnection while standing without manual intervention, thus ensuring an immediate grasp of the balancing hand (H) - pole (15) connection, for use in colder temperatures, appropriately waterproof foot or shoe covers must be provided, which allow a rail guide (3a, 3b) to be positioned as close as possible to the water surface (WO) or even below it, thus further optimizing the center of gravity in favor of improving balance.

7. Water sports equipment according to claim 1, characterized by that the “cross-country ski fins” to be produced according to the invention are designed and suitable in their fin head (4a) such that they transmit the forces introduced perpendicularly thereon from the up- or down-displacement movements of the momentum-transmitting support surface (2) - connecting linkage -(4b) to the fin surfaces (4, 4.1) connected thereon horizontally and rigidly to the pedal axis in a loss-free and elastic manner, by being torsionally connected to the core in a non-rotatable manner, but in the outer grip due to a springy covering, which may be similar to a car tire, The energy initially introduced rigidly is absorbed in a wider area, for example via tough textile fibers embedded in rubber like filaments, and transferred as a restoring force into its waving fin surface in such a way that the fin is able to spring back almost completely to its starting position after its deflection and is ready to immediately absorb, store and release momentum, force and movement in the opposite direction. It is advantageous if the displacement-active surface of the fins has elongated, striated structures that suppress inhibiting turbulence in the displaced water, with the frontal fin head having a slender profile that simultaneously generates lift against the frontal flow, similar to aircraft wings. The fin properties thus offered are also applicable to the inventive arrangement of side, bow, and possibly stern fins (5, 5.1, 5.2), the use and attachment of which is particularly useful for longer, single-hulled boat hulls (1). These fins convert their deflections into energy and propulsion via lateral rocking, but this places the same demands on their fin heads (4a) as on fins that are simply mounted in a tuck position.

8. Water sports equipment according to claims 1-7, characterized by that in the invention of an artificial water cross-country ski trail in sports, as well as in the 25 AMENDED SHEET (ARTICLE 19) Leisure and therapy sector is enabled, In contrast to cross-country skiing, cross-country skiing here is now not only possible on natural and open areas such as lakes and rivers, but preferably near places of residence and very cheaply also in metropolitan areas, as shown, “water cross-country ski trails” (L) are manufactured and constructed using industrially or handcrafted prefabricated building elements, in which water cross-country skiing devices according to the invention are used, which have features such as a central guide channel (32) and next to it artificial (31) or natural water side surfaces (31), in which, via the use of serially produced water cross-country skiing devices according to the invention, fin-operated water cross-country skiing with inventive own or rental equipment can be offered. 9 Water sports equipment according to claims 1-8, characterized by that for recreational use, an application according to the invention should not only be considered with fully assembled devices, but also the distribution of pre-made kits, such as functional units of fin-equipped wings (2) with rail-guided (3a, 3b), roller connections (3c) and water cross-country ski poles (15) seems sensible, which can be mounted on site by amateurs, preferably according to instructions for use, onto suitable boat bodies - such as surfboards. 10 Water sports equipment according to claims 1-9, characterized by that, for the responsible dissemination of the sport according to the invention, among other things due to publicly required safety standards, it is intended to grant regional training and distribution licenses in order to initiate an orderly and acceptable development of the necessary structures. 26 AMENDED SHEET (ARTICLE 19)

Images