Abstract: Systems, apparatuses, and methods for controlling a variable speed boat lift motor. The systems, apparatuses, and methods include a user interface for connection to a variable speed boat lift drive. The user interface transmits a signal to a variable speed boat lift drive that causes the variable speed boat lift drive to rise at a first speed set by a user through the user interface and lower at a second speed set by a user through the user interface.

Abstract: A boat lift with a rotatable head attached to a bracket securable with respect to environmental structure such as a pier which to be capable of lifting a watercraft from the water and while rotating thereof to a position above an adjacent area such a dock area. The lift includes a rotating head assembly having a mounting fin extendable into the interior of a vertically reciprocating mast. A watercraft supporting cradle is secured to the mast to be movable therewith and includes vessel support members for facilitating retaining of a watercraft thereupon. Vertical movement between the mounting fin and the reciprocating mast is facilitated by sliding wear pads positioned therebetween.

Abstract: A floating boatlift assembly includes a cradle assembly suspended between cable handling units arranged on respective spaced parallel float assemblies. An elongated boat is positioned between the float assemblies and over the cradle assembly. The cable handling units are operated to lift the boat into a raised position and permit lowering thereof to float the boat in water.

Abstract: A watercraft lifting system includes a bunk rail assembly, an intermediate frame assembly, a base assembly and a ground support assembly. The bunk rail assembly includes a bunk rail coupled to a load distribution member. The load distribution member is received by the bunk rail such that the bunk rail may rotate by at least a limited amount relative to the load distribution member. The bunk rail may slideably receive a bunk cushion and form a channel therewith for sandwiching a rigid structural member (e.g., a board). The watercraft lifting system may also include contoured clamps that cooperate to distribute and transfer load between frame members. In one embodiment, the contoured clamps include parabolically-shaped inner surfaces.

Abstract: A platform includes main transverse beams (“MTBs”), each supported by at least one hoist. It is determined whether a load on any MTB is different from the load on any other MTB by more than a predetermined amount. An MTB which has a load different from the load on any other MTB by more than a predetermined amount is selected and then vertically moved with respect to the other MTBs within a predetermined safety limit to transfer load between the selected MTB and the other MTBs while monitoring the loads on each MTB and the position of the selected MTB as vertical movement of the selected MTB proceeds. The monitored loads and position are compared with the safety limit; and the movement of the selected MTB stopped when either the desired load transfer is completed or the safety limit has been met.

Abstract: A platform includes main transverse beams (“MTBs”), each supported by at least one hoist. It is determined whether a load on any MTB is different from the load on any other MTB by more than a predetermined amount. An MTB which has a load different from the load on any other MTB by more than a predetermined amount is selected and then vertically moved with respect to the other MTBs within a predetermined safety limit to transfer load between the selected MTB and the other MTBs while monitoring the loads on each MTB and the position of the selected MTB as vertical movement of the selected MTB proceeds. The monitored loads and position are compared with the safety limit; and the movement of the selected MTB stopped when either the desired load transfer is completed or the safety limit has been met.

Abstract: A boat lift includes a lift frame rotatably mounted to a boat dock. A lower trolley with a buoyant body slides on the frame. An upper trolley slides on the frame and is engaged by the boat as it propels itself forward onto the frame when the latter is in a boat receiving position. A linkage connected between the trolleys causes the lower trolley and the buoyant body to slide rearwardly underneath the boat to rotate the lift frame into a final docking position in which the boat is out of the water. The upper trolley is locked into position, thus holding the lower trolley in position through the linkage. The boat is launched by releasing the upper trolley lock, which permits the upper trolley to slide rearwardly, with concomitant forward sliding movement of the lower trolley that permits the frame to rotate and launch the boat from the frame.

Abstract: A high current cursor comprises a outer frame in which a center carriage travels. The center carriage travels between the top and bottom of the outer frame. Movement of the center carriage is limited within the outer frame constraints and its own locking mechanism. Center carriage carries a bend restrictor for an umbilical or lift line. When the center carriage travels down to a predetermined position within the high current cursor, equipment is allowed to exit the high current cursor or is retrieved back into the high current cursor when the bend restrictor reaches a predetermined position within the outer frame, e.g. at its lowest point, allowing dispersal and/or retrieval without obstruction back to a fixed recovery point.

Abstract: A boat lift apparatus is disclosed. The boat lift apparatus includes a base structure having a first frame section erected over a barrier juxtaposed to a first body of water, the base structure having a second frame section that may be cantilevered over the first body of water and a lift frame operatively coupled with the base structure. The boat lift apparatus further includes a cradle assembly including at least one boat support for receiving a boat and carrying the boat across the barrier, the cradle assembly being moveably coupled to the lift frame. The boat lift apparatus further includes at least one hydraulic cylinder secured to the lift frame and operatively connected to the cradle assembly, wherein activation of the at least one hydraulic cylinder moves the cradle assembly up or down in the vertical direction.

Abstract: A platform includes main transverse beams (“MTBs”), each supported by at least one hoist. It is determined whether a load on any MTB is different from the load on any other MTB by more than a predetermined amount. An MTB which has a load different from the load on any other MTB by more than a predetermined amount is selected and then vertically moved with respect to the other MTBs within a predetermined safety limit to transfer load between the selected MTB and the other MTBs while monitoring the loads on each MTB and the position of the selected MTB as vertical movement of the selected MTB proceeds. The monitored loads and position are compared with the safety limit; and the movement of the selected MTB stopped when either the desired load transfer is completed or the safety limit has been met.

Abstract: A boat lift has a boat cradle mounted on a top side of a lift. Wheels are attached to the lift frame, and vertically oriented extendable legs are attached to the lift frame and configured such that with each leg retracted to a fully retracted position the lift frame is supported on the wheels. A leg controller is operative, in a leveling mode, to extend or retract each leg independently to position bottom ends of the legs at different vertical positions on an uneven lake floor as required to support the lift frame in a horizontal orientation with the wheels raised above the lake floor, and is operative in a lifting mode to extend or retract all legs simultaneously to move the lift frame up or down while maintaining the lift frame in the horizontal orientation.

Abstract: A watercraft storage system, a ‘wishbone’ or U-shaped cradle, liftable and rotatable by an overhead crane, comprises adjustable air filled hull supports to either side of a boat hull and a keel support toward the stem of the watercraft. The cradle central opening clears a cantilever storage rack support beam assembly allowing the watercraft to be lowered onto or raised from the cantilever storage rack support beam assembly by an overhead traveling crane. To substantially reduce any longitudinal swaying of the cradle and watercraft during raising and lowering, a system of diagonal anti-sway bracing cables that automatically retract and extend is employed. In the preferred embodiment, the cradle is lowered into a water-filled channel within the storage structure to re-float the watercraft. A watercraft to be stored can be brought into the channel which contains alignment means to accurately position the watercraft over the cradle.

Abstract: A lightweight, knock-down portable watercraft lift or mooring device for small watercraft is disclosed that includes a modular freestanding frame having a pair of spaced supporting foot members, each foot member carrying a pair of spaced support members connected at one end to the foot member, a pair of rails carried by and connected to a second end of the support members. Both the spacing of between the support members and the length of the support members are adjustable allowing the distance between and height of the rails to vary to accommodate watercraft of different widths, water of different depths and create varying lift angles.

Abstract: A lightweight, knock-down portable watercraft lift or mooring device for small watercraft is disclosed that includes a modular freestanding frame having a pair of spaced supporting foot members, each foot member carrying a pair of spaced support members connected at one end to the foot member, a pair of rails carried by and connected to a second end of the support members. Both the spacing of between the support members and the length of the support members are adjustable allowing the distance between and height of the rails to vary to accommodate watercraft of different widths, water of different depths and create varying lift angles.

Abstract: A boat lift drive housing for containing a control box, electric motor and gear head for raising and lowering a boat lift. The housing includes front and rear coaxial openings for access to the gear head. The housing further includes an eyebrow cantilevered over an opening in the housing through which a key switch extends such that the key switch is protected from the sun, rain, snow and ice. The housing further includes a pair of bottom openings, with one bottom housing permitting access to a drive shaft of the electric motor and with the other bottom opening holding a tool for driving the drive shaft of the electric motor. The housing further includes a shape tailored to the control box, electric motor and gear head to minimize extra connections within the housing.

Abstract: A small vessel dock racking system provides a three-sided cradle that is rotatably connected to two lateral supports extending outward from one side of the dock. A person in the water can float the canoe or kayak into the cradle and lift it into a secure vertical storage position on the side of the dock without having to get up on the dock. A pivot point extending out into the water has the advantages of both accommodating freeboard and minimizing the distance between the pivot and the boat's center of gravity, thereby allowing for much less effort in lifting. Depending on the depth of the vessel, the cradle can be dimensioned so that the position of the vessel's center of gravity tends to hold the cradle in a vertical alignment after it's been lifted. Where needed, a cradle latch that can be activated from the water side further secures the storage position.

Abstract: An inflatable lift system for to lift and maneuver a boat lift upon a body of water. The inflatable lift system includes a floatation assembly including a plurality of air inflatable floatation members for lifting a movable structure, and also includes a support assembly for supporting and securing the air inflatable floatation members to the movable structure.

Abstract: A boat lift system that utilizes a solar module system. The solar module system includes a flexible solar film that is secured to a magnetic member that is electrically connected to a junction box. The junction box additionally is electrically connected to the electrical system of the boat lift such that electricity generated from the flexible solar film is transferred to the electrical system of the boat lift.

Abstract: An adjustable lift, such as a boat lift, or an adjustable apparatus mountable to a boat lift, comprising a frame supporting a keyway, a shaft and a screw along which a hub assembly travels. An axle may extend from the hub assembly and support a wheel, such that translation of the hub assembly along screw raises and lowers the wheel with respect to the frame members of the lift. In this way, the lift may be rolled into place, with its wheels then raised, so that frame members and/or feet of the lift rest on a lake bed or other surface. When wanting to move the lift, a user may rotate the screw in an opposite direction, lowering the wheel with respect to the frame member, freeing lift frame members and feet from the lake bed and allowing the user to roll the lift away.

Abstract: An apparatus for hoisting a ship. A transfer truck located on the shore moves to the interior of a raising/lowering lift by means of a set of movable rails so as to be able to unload the ship floating on a water surface. Lift-side support blocks, which are spaced apart from each other, are gradually raised under water to float the ship on the water surface. Truck-side support blocks, which are spaced apart from each other in a manner similar to the lift-side support blocks, move to the interior of the raising/lowering lift. Thereby, the lift-side support blocks, which are spaced apart from each other, are lowered through gaps between the truck-side support blocks while crossing the truck-side support blocks so as to allow the ship to be safely unloaded.

Abstract: In one aspect of watercraft automation and aquatic data utilization for aquatic efforts, an anchor point is obtained and a watercraft position maintenance routine is actuated to control the watercraft to maintain association with the anchor point. In another aspect, prior aquatic effort data is obtained in association with an anchor point. In yet another aspect, current aquatic effort data is generated in association with an anchor point. In still another aspect, current aquatic effort data and prior aquatic effort data are utilized for prediction generation. In yet another aspect, current aquatic effort data and prior aquatic effort data are utilized to obtain another anchor point for a watercraft.

Abstract: A hydraulic boat lift assembly will raise and lower a boat cradle remotely, and will securely lock the cradle in an uppermost storage position. The lift as provided with a manual mechanism for unlocking the cradle from its uppermost storage position for operation when the hydraulic system is not available. The lift has a support frame that is mountable on the outside of the transom of a boat with hydraulic connections to a hydraulic system and controls within the boat. A lift mechanism connected to the support frame raises and lowers a cradle that supports a small boat or tender. The lift mechanism includes one or more hydraulic lift cylinders. In a retracted position of the lift cylinder, the cradle is elevated above the water in a storage position when the boat is under way. To ensure security of the tender, the lift mechanism employs a lock cylinder that prevents inadvertent motion of the lift cylinder from the retracted position by mechanical and hydraulic mechanisms.

Abstract: An assembly for attaching to a boat lift 12 includes a boat lift 12 attachment mechanism 70 for attaching to the boat lift 12; an outer support 24; an inner support 26 slidable within an interior of the outer support 24; a tire 22 attached to the inner support 26; and a stop member 82 extending from the outer support 24 to engage the tire 22 when the inner support 26 is retracted into the outer support 24. An outer surface of the inner support 26 is configured to be mateable with an inner surface of the outer support 24, thereby preventing rotation therein while permitting longitudinal movement with respect to the outer support 24. In another aspect, an assembly includes an axle 54 attached to the inner support 26 for the attachment of a ground engaging member. A method of leveling a boat lift 12 includes causing substantially vertical movements of first and second portions of the boat lift 12 until the boat lift 12 is horizontally level.

Abstract: A boat lift uses the boat's own propulsive force to lift the boat out of the water. The boat lift comprises a lift frame mounted to a boat dock for rotation, and in a boat receiving position is rotated so that the boat can propel itself onto a boat cradle on the lift frame. A lower trolley slidably mounted on the frame includes a buoyant body in the water for exerting an upward force on the frame. An upper trolley slidably mounted on the frame is engaged by the boat as it propels itself forward onto the boat cradle. The upper trolley is linked to the lower trolley to cause the lower trolley to slide rearwardly under the boat, thus moving the buoyant body rearwardly and rotating the lift frame into a final docking position in which the boat is lifted out of the water. The upper trolley is locked into position, thus locking the lower trolley in position through the linkage between them, and a boat retainer actuated by the lower trolley engages the rear of the boat to hold it on the boat cradle.

Abstract: A watercraft support and tote device having a frame sub-assembly having a first frame member and a second frame member and at least one support member; a power output member; a hydraulic sub-assembly having a hydraulic vessel, a control system, and a conduit; at least one ground engaging wheel; a drive member; a winch; and a plurality of watercraft support members.

Abstract: A transportation system and method of transferring a barge from a waterway and to a refurbishing system. The transportation system includes transport systems that move the barge out of water and onto to a position away from the water, then moves the barge into the refurbishing system. The transport systems then move the refurbished barge back into the water.

Abstract: A system and method in which a buoyant central docking station captures, lifts and couples one or more other sea vessels is disclosed, wherein a flexible, modularized production system is quickly realized on a cost effective basis. The capabilities of a number of older, less expensive, readily available vessels are combined to achieve an effective FPSO substitute that allows lower producing fields to be explored and produced in a profitable manner. The time horizon between initiation and consummation of field operations is reduced, and older vessels that might otherwise be scrapped or retired are again made useful and seaworthy in a safe and profitable exploration and production environment.

Abstract: A method and apparatus for removing debris from an ocean floor or seabed employs a subsea debris basket. The basket eliminates the absolute necessity of a cargo barge or any other supporting vessel that might be required to remain in a field until the objects on the ocean floor can be lifted. The present invention provides a non-weather sensitive solution. The present invention affords the safe operation in that all lifting and lowering is performed in a subsea environment next to the ocean floor or seabed. The present invention enables operation to be completed with the use of an ROV or remotely operated vehicle. The present invention provides improved offshore efficiency, less time being required to recover debris from the seabed to the underwater salvage basket or debris basket. The present invention enables the possibility of use of an A-frame or simple crane to lower debris into a subsea basket. The basket can be reused or redeployed in the field if desired.

Abstract: An inflatable lift system for to lift and maneuver a boat lift upon a body of water. The inflatable lift system includes a floatation assembly including a plurality of air inflatable floatation members for lifting a movable structure, and also includes a support assembly for supporting and securing the air inflatable floatation members to the movable structure.

Abstract: The invention provides a method for the transport of a civil engineering structure in an aquatic medium. According to this method: at least one float is associated with the civil engineering structure in such a way as to ensure that the said civil engineering structure floats stably in an aquatic medium, the said float surrounding the civil engineering structure and a bottom portion of the civil engineering structure extending below the said float, and the civil engineering structure and the associated float are caused to move in the aquatic medium to a desired position.

Abstract: An anti-theft security system for boats on boat lifts, which also provides for stability to eliminate boat swaying on the lift during wind storms. The system includes two opposing secondary side rails configured to move laterally along an underside of the primary boat lift I-beams. The side rails are interlocked within receiving brackets mounted to the boat lift posts, using a locking device that locks one of the side rails to the post mounted brackets on the dock pier side. The opposite secondary side rail includes an attached pull bar that allows a person to place the rail in position for locking or to pull the opposite side rail away from the lift posts to lower the boat into the water. The pull bar handle is interlocked with the rail nearest the dock pier side.

Abstract: An adjustable lift, such as a boat lift, or an adjustable apparatus mountable to a boat lift, comprising a frame supporting a keyway, a shaft and a screw along which a hub assembly travels. An axle may extend from the hub assembly and support a wheel, such that translation of the hub assembly along screw raises and lowers the wheel with respect to the frame members of the lift. In this way, the lift may be rolled into place, with its wheels then raised, so that frame members and/or feet of the lift rest on a lake bed or other surface. When wanting to move the lift, a user may rotate the screw in an opposite direction, lowering the wheel with respect to the frame member, freeing lift frame members and feet from the lake bed and allowing the user to roll the lift away.

Abstract: The invention relates to a device for a watercraft for picking up and launching boats. The device comprises an extension arm that is coupled in such a manner that it can swing freely on the watercraft, that extends at an acute angle in relation to the surface of the water and floats in water by means of floats. The extension arm comprises guide tracks for a boat retrieving device that is maintained on the extension arm in a longitudinally displaceable manner. The boat retrieving device comprises a holding head that is articulated in a displaceable manner on a running part guided on the guide rails, about an axis that is horizontal and approximately transversal in relation to the extension arm. The running part is connected to the drive means for longitudinally displacing the boat retrieving device. The holding head comprises at least one adjusting means that acts upon its adjusting movement about the horizontal axis.

Abstract: A boatlift for use with small, manual or paddle or oar powered watercraft (such as canoes and kayaks) is provided with a guide rails on either side of the boat lift, which can be utilized by a boater to propel or urge his/her watercraft onto the boatlift. In addition, that boatlift is provided with an entrance/exit assist member which can be used by boaters with impaired leg function to enter and exit from the watercraft. The boatlift can be provided with a bench system which enables disabled persons to more easily enter and exit from small watercraft supported by the boatlift.

Abstract: An apparatus and method are described for lifting a boat out of water. An improved boat lift having at least one support beam upon which the weight of a boat rests, the support beams having an interior wherein components of a cable drive system are mounted, provides lifting force through operation of the cable drive system, which withdraws the support cables to within the interior of the support beams, the cables attached at one of their ends to fixed points external to the beam.

Abstract: A boat lift system for raising and lowering a multi-hulled boat from and into a body of water, the boat including first and second laterally spaced apart hull structures, includes a carrier assembly and a drive system. The carrier assembly is configured to hold the boat. The carrier assembly includes a crossbeam having a length and first and second cradle assemblies spaced apart along the length of the crossbeam and secured to the crossbeam. Each of the first and second cradle assemblies is configured to receive a respective one of the first and second hull structures and includes a coupling bracket and a pair of longitudinally extending runners each secured to the coupling bracket and positioned to receive and support the respective one of the first and second hull structures. The coupling bracket connects and resists lateral separation between the runners. The drive system is operable to selectively raise and lower the carrier assembly.

Abstract: An apparatus for hoisting a ship. A transfer truck located on the shore moves to the interior of a raising/lowering lift by means of a set of movable rails so as to be able to unload the ship floating on a water surface. Lift-side support blocks, which are spaced apart from each other, are gradually raised under water to float the ship on the water surface. Truck-side support blocks, which are spaced apart from each other in a manner similar to the lift-side support blocks, move to the interior of the raising/lowering lift. Thereby, the lift-side support blocks, which are spaced apart from each other, are lowered through gaps between the truck-side support blocks while crossing the truck-side support blocks so as to allow the ship to be safely unloaded.

Abstract: This document is directed toward a stabilizing system that is engageable with a watercraft lift assembly. The system includes a piling bracket, at least one piling bracket keyhole in the piling bracket, a lift-block having at least one keyhole pin extending from a first side of said lift-block toward said at least one piling bracket keyhole, and a stabilizing beam, for supporting a watercraft lift assembly cradle. The stabilizing beam is attached to a second side of said lift-block.

Abstract: A platform includes main transverse beams (“MTBs”), each supported by at least one hoist. It is determined whether a load on any MTB is different from the load on any other MTB by more than a predetermined amount. An MTB which has a load different from the load on any other MTB by more than a predetermined amount is selected and then vertically moved with respect to the other MTBs within a predetermined safety limit to transfer load between the selected MTB and the other MTBs while monitoring the loads on each MTB and the position of the selected MTB as vertical movement of the selected MTB proceeds. The monitored loads and position are compared with the safety limit; and the movement of the selected MTB stopped when either the desired load transfer is completed or the safety limit has been met.

Abstract: A watercraft lifting system includes a bunk rail assembly, an intermediate frame assembly, a base assembly and a ground support assembly. The bunk rail assembly includes a bunk rail coupled to a load distribution member. The load distribution member is received by the bunk rail such that the bunk rail may rotate by at least a limited amount relative to the load distribution member. The bunk rail may slideably receive a bunk cushion and form a channel therewith for sandwiching a rigid structural member (e.g., a board). The watercraft lifting system may also include contoured clamps that cooperate to distribute and transfer load between frame members. In one embodiment, the contoured clamps include parabolically-shaped inner surfaces.

Abstract: A lifting apparatus includes a lift arm for carrying a platform or cradle and is pivotally attached to a base for movement between lowered and raised positions. A crank arm is pivotal with the base and a connector arm is pivotal with the lift arm. The crank arm and connector arm are pivotally connected to each other for rotation about a common pivot axis. Rotation of the crank arm by an actuator moves the crank arm and connector arm combination through a top dead center alignment a lowered over center alignment with the lift arm movable from the lowered position to the raised position during operating positions of the apparatus, and to a raised over center alignments with limited movement of the lift arm in the raised position for providing a locking position of the apparatus thus eliminating a need for typical additional locking mechanism.

Abstract: A boat lift with a rotatable head attached to a bracket securable with respect to environmental structure such as a pier which to be capable of lifting a watercraft from the water and while rotating thereof to a position above an adjacent area such a dock area. The lift includes a rotating head assembly having a mounting fin extendable into the interior of a vertically reciprocating mast. A watercraft supporting cradle is secured to the mast to be movable therewith and includes vessel support members for facilitating retaining of a watercraft thereupon. Vertical movement between the mounting fin and the reciprocating mast is facilitated by sliding wear pads positioned therebetween.

Abstract: A boatlift for use with small, manual or paddle or oar powered watercraft (such as canoes and kayaks) is provided with a guide rails on either side of the boat lift, which can be utilized by a boater to propel or urge his/her watercraft onto the boatlift. In addition, that boatlift is provided with an entrance/exit assist member which can be used by boaters with impaired leg function to enter and exit from the watercraft.

Abstract: A programmable boatlift system having a cable extending up from one end of a boatlift cradle, across through a shaft attached to a motor, and down to an opposite end of the boatlift cradle. A position sensor having an idler sheave is placed on the cable, or a position sensor having a collar is placed on the shaft. The motor turns the shaft to cause the cable to move across the roller sheave, or to cause the collar to rotate, to raise or lower the boatlift cradle. The position sensor produces an output signal proportional to the distance the cable travels over the idler sheave or proportional to the number of rotations of the collar. An electronic control circuit uses the output signal to infer the vertical position of the boatlift cradle and to position the boatlift cradle as desired.

Abstract: In a watercraft storage system a “wishbone” or U-shaped cradle liftable and rotatable by an overhead crane comprises adjustable air filled hull supports to either side of a boat hull and a keel support toward the stem of the watercraft. The cradle central opening clears a cantilever storage rack support beam assembly allowing the watercraft lo be lowered onto or raised from the cantilever storage rack support beam assembly by an overhead traveling crane. To substantially reduce any longitudinal swaying of the cradle and watercraft during raising and lowering, a system or diagonal anti-sway bracing cables that automatically retract and extend is employed. In the preferred embodiment, the cradle is lowered into a water-filled channel within the storage structure to re-float the watercraft. A watercraft to be stored can be brought into the channel which contains alignment means to accurately position the watercraft over the cradle.

Abstract: A method of retrieving a boat from the water by supporting the boat by two lift sections, each of which has an inflatable bunker and a cradle structure that supports and positions the bunker. The lift sections are connected to a mobile support structure which brings these lift sections to a location near the water into which the boat is to be retrieved. The lift sections are lowered and positioned into the water and the boat is floated into the lift region between them. The lift sections are raised upwardly to carry the boat from the water and to another location over a land surface.

Abstract: A programmable boatlift system having a cable extending up from one end of a boatlift cradle, across to a shaft attached to a motor, and down to an opposite end of the boatlift cradle. The cable passes through a hole in the shaft. A position sensor having an idler sheave is placed on the cable. The motor winds or unwinds the cable around the shaft to cause the cable to move across the roller sheave to raise or lower the boatlift cradle. The position sensor produces an output signal proportional to the distance the cable travels over the idler sheave as the cable causes the idler sheave to rotate. An electronic control circuit uses the output signal to infer the vertical position of the boatlift cradle and to position the boatlift cradle as desired.

Abstract: A lift for low profile watercraft is substantially comprised of modular extruded components and minimal or no welded parts. The lift comprises a tower to be mounted to a dock. A winch is mounted on the tower for raising and lowering a carriage assembly engaged with the tower. The carriage assembly is comprised of a pair of forks in the form of a forked v-configuration, the intersection of the two arms retained by a carriage that engages and travels along a channeled track in the tower, transported by a winch-driven cable. Further comprising the carriage assembly and traversing the arms of the fork are two bunk assemblies, each bunk assembly comprising a pivot bar adjustably attached to both carriage forks. Connected to each bunk pivot bar and pivoting therewith is a bunk board, disposed upon which is a bunk for engaging the hull of the watercraft.

Abstract: An air-displacement boat lift control that allows a user to raise an air-displacement boat lift in a single motion and also lower an air-displacement boat lift in a separate single motion. The boat lift control controllably couples a ball valve with a throttle-like lever arm having a forward (raise), reverse (lower), and neutral position.

Abstract: A programmable boatlift system having a cable extending up from one end of a boatlift cradle, across through a shaft attached to a motor, and down to an opposite end of the boatlift cradle. A position sensor having an idler sheave is placed on the cable, or a position sensor having a collar is placed on the shaft. The motor turns the shaft to cause the cable to move across the roller sheave, or to cause the collar to rotate, to raise or lower the boatlift cradle. The position sensor produces an output signal proportional to the distance the cable travels over the idler sheave or proportional to the number of rotations of the collar. An electronic control circuit uses the output signal to infer the vertical position of the boatlift cradle and to position the boatlift cradle as desired.