초록 ▼

A watercraft lift with hydraulically actuated arms which self-installs a fitted three-dimensional boat or other watercraft cover on a powerboat or other watercraft. Control logic allows for cover operation only when the lift is raised, and has a single control for both the lift and cover system. A s

A watercraft lift with hydraulically actuated arms which self-installs a fitted three-dimensional boat or other watercraft cover on a powerboat or other watercraft. Control logic allows for cover operation only when the lift is raised, and has a single control for both the lift and cover system. A spring-tensioned roller keeps the cover tight and self-rolls the cover on the roller when the actuated arms are pivoted forward. The roller is hidden behind the watercraft when in a “cover-on” position.

대표청구항 ▼

1. A watercraft lift for lifting and lowering a watercraft having sides and a bottom, with a bow and a stern, the watercraft lift being positionable in a body of water, comprising: a freestanding frame having a front end and a rear end;at least one watercraft support movably connected to the frame a

1. A watercraft lift for lifting and lowering a watercraft having sides and a bottom, with a bow and a stern, the watercraft lift being positionable in a body of water, comprising: a freestanding frame having a front end and a rear end;at least one watercraft support movably connected to the frame and movable between a lowered support position and a raised support position, the watercraft support being arranged to engage and lift the watercraft when positioned thereon between the lowered support position and the raised support position;port and starboard pivot arms, each having a lower end portion pivotally movably attached to the frame and an upper end portion, the port and starboard pivot arms being pivotally movable between a forward position wherein the upper end portions of the port and starboard pivot arms are positioned toward the bow of the watercraft when supported by the watercraft support in the raised support position and a rearward position wherein the upper end portions of the port and starboard pivot arms are positioned toward the stern of the watercraft when supported by the watercraft support in the raised support position;at least one actuation member operatively connected to the port and starboard pivot arms to selectively and in unison pivotally move the port and starboard pivot arms between the forward and rearward positions;a roller having a port end portion rotatably supported by the upper end portion of the port pivot arm and a starboard end portion rotatably supported by the upper end portion of the starboard pivot arm for travel with the upper end portions of the port and starboard pivot arms as they are pivotally moved between the forward and rearward positions;a roller actuation member operatively connected to the roller to apply a rotational force thereto as the upper end portions of the port and starboard pivot arms are pivotally moved from the rearward position to the forward position;a forwardly extending securing member having a rearward end portion attached to the frame at a location lower than the bow of the watercraft and a forward end potion positioned lower and below the bow of the watercraft when the watercraft is positioned on the watercraft support with the watercraft support in the lowered support position;a watercraft cover sized to lengthwise extend over the watercraft, the cover having a forward end portion and a rearward end portion, and port and starboard side cover portions, the port side cover portion being sized to cover substantially the full port side of the watercraft and the starboard side cover portion being sized to cover substantially the full starboard side of the watercraft when the port and starboard pivot arms are moved to the rearward position and the watercraft is supported by the watercraft support in the raised support, the cover having a port side pocket extending along an edge portion of the port side cover portion and a starboard side pocket extending along an edge portion of the starboard side cover portion;an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member having a port side portion extending through the port side pocket of the cover and terminating in an end portion and a starboard side portion extending through the starboard side pocket of the cover and terminating is an end portion, the end portions of the port and starboard side member portions of the perimeter member being attached to the roller, the length of the port and starboard side portions of the perimeter member being sized such that as the cover is unwound from the roller as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position and the port and starboard pivot arms approach the rearward position, the port and starboard side portions of the perimeter member are stretched into a taut state such that the taut port and starboard side portions of the perimeter member apply downward force along the length of the port and starboard edge portions of the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position;a flexible first attachment member having a first portion attached to the forward end portion of the cover and a second portion attached to the securing member, the flexible first attachment member comprising a flexible port attachment member having a first portion attached to a port side of the forward end portion of the cover and a second portion attached to the securing member, and a flexible starboard attachment member having a first portion attached to a starboard side of the forward end portion of the cover and a second portion attached to the securing member;an elastic second attachment member having a first portion attached to the rearward end portion of the cover and a second portion attached to the roller, the length of the elastic second attachment member being sized such that as the port and starboard pivot arms approach the rearward position, the elastic second attachment member is stretched sufficiently to apply a rearward force on the rearward end portion of the cover sufficient to place the cover in a taut state; andwherein the cover is wound about the roller when the upper end portions of the port and starboard pivot arms are in the forward position with the flexible first attachment member attached to the forward end portion of the cover and to the securing member, and progressively unwinds from the roller and is placed in position extending lengthwise covering the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position when the watercraft is supported by the watercraft support in the raised support position, and wherein the cover is progressively wound about the roller and removed from covering the watercraft by the rotational force applied to the roller by the roller actuation member as the upper end portions of the port and starboard pivot arms are pivotally moved from the rearward position to the forward position when the watercraft is supported by the watercraft support in the raised support position. 2. The watercraft lift of claim of claim 1 wherein the forward end portion of the cover includes port and starboard wings to which the first portion of the first attachment member is attached. 3. The watercraft lift of claim 1 further including a spreader member extending between and spacing apart the port attachment member and the starboard attachment member at a position above the securing member. 4. The watercraft lift of claim 1 wherein the forward end portion of the cover forms a pocket sized to receive the bow of the watercraft therein, and the first attachment member comprises a port member attached to a port side of the forward end portion of the cover rearward of the pocket and a starboard member attached to a starboard side of the forward end portion of the cover rearward of the pocket. 5. The watercraft lift of claim 1 wherein the securing member includes a bow sprit having a forward end portion to which the second portion of the flexible first attachment member is attached and a rearward end portion attached to the frame, the forward end portion of the bow sprit being centrally located and below the bow of the watercraft when the watercraft is positioned on the watercraft support. 6. The watercraft lift of claim 1 wherein the cover has internal handles. 7. The watercraft lift of claim 1 wherein when the port and starboard pivot arms are moved to the forward position the roller is located forward of the bow of the watercraft when supported by the watercraft support in the raised support position, and when the port and starboard pivot arms are moved to the rearward position the roller is located rearward of the stern of the watercraft and lower than fifty percent of the port and starboard sides of the watercraft when supported by the watercraft support in the raised support position. 8. The watercraft lift of claim 1 wherein when the port and starboard arms are moved to the forward position the roller is located forward of the bow of the watercraft when supported by the watercraft support in the raised support position, and when the port and starboard arms are moved to the rearward position the roller is located rearward of the stern of the watercraft and at or below the waterline of the watercraft when supported by the watercraft support in the raised support position. 9. The watercraft lift of claim 1 wherein the cover is wound about the roller in a first rotational direction when the upper end portions of the port and starboard pivot arms are in the forward position, and the length of the port and starboard side portions of the perimeter member are sized such that as the cover is unwound from the roller as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position and the port and starboard pivot arms approach the rearward position, the end portions of the port and starboard side portions of the perimeter member are wound around the roller in a second rotational direction opposite the first rotational direction sufficient to stretch the port and starboard side portions of the perimeter member into the taut state such that the taut port and starboard side portions of the perimeter member apply downward force along the length of the port and starboard edge portions of the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 10. The watercraft lift of claim 1 wherein the perimeter member is adjustable. 11. The watercraft lift of claim 5 wherein the forward end portion of the bow sprit is located below the water line and below the bottom of the watercraft when the watercraft is positioned on the watercraft support with the watercraft support in the lowered support position and the watercraft lift positioned in the body of water. 12. The watercraft lift of claim 1 wherein the actuation member operatively connected to the port and starboard pivot arms includes at least one hydraulic cylinder. 13. The watercraft lift of claim 12 wherein further including a single control configured to switch automatically from a lifting mode controlling the watercraft support lifting of the watercraft between the lowered support position and the raised support position, and a cover mode controlling the actuation member operatively connected to the port and starboard pivot arms. 14. The watercraft lift of claim 1 further including a remote control which is capable of remotely controlling the operation of the actuation member operatively connected to the port and starboard pivot arms. 15. The watercraft lift of claim 1 wherein the actuation member operatively connected to the port and starboard pivot arms includes a port hydraulic cylinder connected to the port pivot arm for pivoting of the port pivot arm and a starboard hydraulic cylinder connected to the starboard pivot arm for pivoting of the starboard pivot arm. 16. The watercraft lift of claim 15 further including a hydraulic flow divider connected to the port and starboard hydraulic cylinders to control the port and starboard hydraulic cylinders for pivoting of the port and starboard pivot arms in unison. 17. The watercraft lift of claim 1 wherein the upper end portion of each of the port and starboard pivot arms is selectively lengthwise adjustable relative to the upper end portion to adjust the length of the port and starboard pivot arms. 18. The watercraft lift of claim 1 wherein the frame location of the lower end portion pivotal attachment to the frame of each of the port and starboard pivot arms is selectively longitudinally adjustable along a portion of the frame. 19. The watercraft lift of claim 1 wherein the actuation member operatively connected to the port and starboard pivot arms includes a port hydraulic cylinder connected to the port pivot arm for pivoting of the port pivot arm and having a lower end portion pivotally attached to the frame and a starboard hydraulic cylinder connected to the starboard pivot arm for pivoting of the starboard pivot arm and having a lower end portion pivotally attached to the frame, the frame attachment locations of the lower end portions of the port and starboard hydraulic cylinders are selectively adjustable along a portion of the frame. 20. A watercraft lift for lifting and lowering a watercraft having sides and a bottom, with a bow and a stern, the watercraft lift being positionable in a body of water, comprising: a freestanding frame having a front end and a rear end;at least one watercraft support movably connected to the frame and movable between a lowered support position and a raised support position, the watercraft support being arranged to engage and lift the watercraft when positioned thereon between the lowered support position and the raised support position;port and starboard pivot arms, each having a lower end portion pivotally movably attached to the frame and an upper end portion, the port and starboard pivot arms being pivotally movable between a forward position wherein the upper end portions of the port and starboard pivot arms are positioned toward the bow of the watercraft when supported by the watercraft support in the raised support position and a rearward position wherein the upper end portions of the port and starboard pivot arms are positioned toward the stern of the watercraft when supported by the watercraft support in the raised support position;at least one actuation member operatively connected to the port and starboard pivot arms to selectively and in unison pivotally move the port and starboard pivot arms between the forward and rearward positions;a roller having a port end portion rotatably supported by the upper end portion of the port pivot arm and a starboard end portion rotatably supported by the upper end portion of the starboard pivot arm for travel with the upper end portions of the port and starboard pivot arms as they are pivotally moved between the forward and rearward positions;a roller actuation member operatively connected to the roller to apply a rotational force thereto as the upper end portions of the port and starboard pivot arms are pivotally moved from the rearward position to the forward position;a watercraft cover sized to lengthwise extend over the watercraft, the cover having a forward end portion and a rearward end portion, and port and starboard side portions, the port side portion being sized to cover substantially the full port side of the watercraft and the starboard side portion being sized to cover substantially the full starboard side of the watercraft when the port and starboard pivot arms are moved to the rearward position and the watercraft is supported by the watercraft support in the raised support position;a first attachment member having a first portion attached to the forward end portion of the cover and a second portion attached to a securing member, the first attachment member comprises a flexible port attachment member having a first portion attached to a port side of the forward end portion of the cover and a second portion attached to the securing member, and a flexible starboard attachment member having a first portion attached to a starboard side of the forward end portion of the cover and a second portion attached to the securing member;a second attachment member having a first portion attached to the rearward end portion of the cover and a second portion attached to the roller; andwherein the cover is wound about the roller when the upper end portions of the port and starboard pivot arms are in the forward position with the first attachment member attached to the forward end portion of the cover and to the securing member, and progressively unwinds from the roller and is placed in position extending lengthwise covering the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position when the watercraft is supported by the watercraft support in the raised support position, and wherein the cover is progressively wound about the roller and removed from covering the watercraft by the rotational force applied to the roller by the roller actuation member as the upper end portions of the port and starboard pivot arms are pivotally moved from the rearward position to the forward position when the watercraft is supported by the watercraft support in the raised support position. 21. The watercraft lift of claim 20 wherein when the port and starboard pivot arms are moved to the forward position the roller is located forward of the bow of the watercraft when supported by the watercraft support in the raised support position, and when the port and starboard pivot arms are moved to the rearward position the roller is located rearward of the stern of the watercraft and lower than fifty percent of the port and starboard sides of the watercraft when supported by the watercraft support in the raised support position. 22. The watercraft lift of claim 20 wherein the securing member is attached to the frame at a location lower than the bow of the watercraft and below the water line when the watercraft is positioned on the watercraft support with the watercraft support in the lowered support position and the watercraft lift positioned in the body of water. 23. The watercraft lift of claim 20 wherein the cover has a port side pocket extending along an edge portion of the port side portion and a starboard side pocket extending along an edge portion of the starboard side portion, and the watercraft lift further includes an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member having a port side portion extending through the port side pocket of the cover and terminating in an end portion and a starboard side portion extending through the starboard side pocket of the cover and terminating is an end portion, the end portions of the port and starboard side portions of the perimeter member being attached to the roller, the length of the port and starboard side portions being sized such that as the cover is unwound from the roller as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position and the port and starboard pivot arms approach the rearward position, the port and starboard side portions of the perimeter member are stretched into a taut state such that the taut port and starboard side portions of the perimeter member apply downward force along the length of the port and starboard edge portions of the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 24. The watercraft lift of claim 23 wherein the cover is wound about the roller in a first rotational direction when the upper end portions of the port and starboard pivot arms are in the forward position, and the length of the port and starboard side portions of the perimeter portion are sized such that as the cover is unwound from the roller as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position and the port and starboard pivot arms approach the rearward position, the end portions of the port and starboard side portions of the perimeter member are wound about the roller in a second rotational direction opposite the first rotational direction sufficient to stretch the port and starboard side portions of the perimeter member into the taut state such that the taut port and starboard side portions of the perimeter member apply downward force along the length of the port and starboard edge portions of the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 25. The watercraft lift of claim 20 wherein the cover is wound about the roller in a first rotational direction when the upper end portions of the port and starboard pivot arms are in the forward position, and the watercraft lift further includes an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member having a port side portion engaging the edge portion of the port side portion of the cover and terminating in an end portion and a starboard side portion engaging the edge portion of the starboard side portion of the cover and terminating is an end portion, the end portions of the port and starboard side portions of the perimeter member being attached to the roller, the length of the port and starboard side portions being sized such that as the cover is unwound from the roller as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position and the port and starboard pivot arms approach the rearward position, the end portions of the port and starboard side portions of the perimeter member are wound about the roller in a second rotational direction opposite the first rotational direction sufficient to stretch the port and starboard side portions of the perimeter member into a taut state such that the taut port and starboard side portions of the perimeter member apply downward force along the length of the port and starboard edge portions of the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 26. The watercraft lift of claim 20 further including an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member engaging the port and starboard side portions of the cover and terminating in port and starboard end portions attached to the roller, the perimeter member being sized in length such that as the cover is unwound from the roller as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position and the port and starboard pivot arms approach the rearward position, the perimeter member is stretched into a taut state such that the taut the perimeter member applies downward force to the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 27. The watercraft lift of claim 20 wherein the second attachment member is elastic and the length of the elastic second attachment member is sized such that as the port and starboard pivot arms approach the rearward position, the elastic second attachment member is stretched sufficiently to apply a rearward force on the rearward end portion of the cover sufficient to place the cover in a taut state. 28. The watercraft lift of claim 27 further including an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member being attached to port and starboard side portions of the cover and terminating in port and starboard end portions attached to the roller, the perimeter member being sized in length such that as the cover is unwound from the roller as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position and the port and starboard pivot arms approach the rearward position, the perimeter member is stretched into a taut state such that the taut the perimeter member applies downward force to the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 29. The watercraft lift of claim 20 wherein the roller actuation member is a torsion spring operatively connected to the roller to apply a rotational force thereto as the upper end portions of the port and starboard pivot arms are pivoted from the rearward position to the forward position, and wherein the cover is progressively wound about the roller and removed from covering the watercraft by the rotational force applied to the roller by the torsion spring as the upper end portions of the port and starboard pivot arms are pivoted from the rearward position to the forward position when the watercraft is supported by the watercraft support in the raised support position. 30. The watercraft lift of claim 20 wherein the first attachment member is flexible. 31. The watercraft lift of claim 20 further including a spreader member extending between and spacing apart the port attachment member and the starboard attachment member at a position above the securing member. 32. The watercraft lift of claim 20 wherein the second attachment member is elastic with the length of the elastic second attachment member being sized such that as the port and starboard pivot arms approach the rearward position, the elastic second attachment member is stretched sufficiently to apply a rearward force on the rearward end portion of the cover sufficient to place the cover in a taut state. 33. The watercraft lift of claim 32 further including an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member being attached to port and starboard side portions of the cover and terminating in port and starboard end portions attached to the roller, the perimeter member being sized in length such that as the cover is unwound from the roller as the upper end portions of the port and starboard pivot arms are pivotally moved from the forward position to the rearward position and the port and starboard pivot arms approach the rearward position, the perimeter member is stretched into a taut state such that the taut the perimeter member applies downward force to the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard pivot arms are pivotally moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 34. A watercraft lift for lifting and lowering a watercraft having sides and a bottom, with a bow and a stern, the watercraft lift being positionable in a body of water, comprising: a freestanding frame having a front end and a rear end;at least one watercraft support movably connected to the frame and movable between a lowered support position and a raised support position, the watercraft support being arranged to engage and lift the watercraft when positioned thereon between the lowered support position and the raised support position;port and starboard arms, each having a lower end portion movably attached to the frame and an upper end portion, the port and starboard arms being movable between a forward position wherein the upper end portions of the port and starboard arms are positioned toward the bow of the watercraft when supported by the watercraft support in the raised support position and a rearward position wherein the upper end portions of the port and starboard arms are positioned toward the stern of the watercraft when supported by the watercraft support in the raised support position;at least one actuation member operatively connected to the port and starboard arms to selectively and in unison move the port and starboard arms between the forward and rearward positions;a roller having a port end portion rotatably supported by the upper end portion of the port arm and a starboard end portion rotatably supported by the upper end portion of the starboard arm for travel with the upper end portions of the port and starboard arms as they moved between the forward and rearward positions;a roller actuation member operatively connected to the roller to apply a rotational force thereto as the upper end portions of the port and starboard arms are moved from the rearward position to the forward position;a watercraft cover sized to lengthwise extend over the watercraft, the cover having a forward end portion and a rearward end portion, and port and starboard side portions, the port side portion being sized to cover substantially the full port side of the watercraft and the starboard side portion being sized to cover substantially the full starboard side of the watercraft when the port and starboard arms are moved to the rearward position and the watercraft is supported by the watercraft support in the raised support position;a first attachment member having a first portion attached to the forward end portion of the cover and a second portion attached to a securing member, the first attachment member comprising a flexible port attachment member having a first portion attached to a port side of the forward end portion of the cover and a second portion attached to the securing member, and a flexible starboard attachment member having a first portion attached to a starboard side of the forward end portion of the cover and a second portion attached to the securing member;a second attachment member having a first portion attached to the rearward end portion of the cover and a second portion attached to the roller; andwherein the cover is wound about the roller when the upper end portions of the port and starboard arms are in the forward position with the first attachment member attached to the forward end portion of the cover and to the securing member, and progressively unwinds from the roller and is placed in position extending lengthwise covering the watercraft as the upper end portions of the port and starboard arms are moved from the forward position to the rearward position when the watercraft is supported by the watercraft support in the raised support position, and wherein the cover is progressively wound about the roller and removed from covering the watercraft by the rotational force applied to the roller by the roller actuation member as the upper end portions of the port and starboard arms are moved from the rearward position to the forward position when the watercraft is supported by the watercraft support in the raised support position. 35. The watercraft lift of claim 34 wherein when the port and starboard arms are moved to the forward position the roller is located forward of the bow of the watercraft when supported by the watercraft support in the raised support position, and when the port and starboard arms are moved to the rearward position the roller is located rearward of the stern of the watercraft and lower than fifty percent of the port and starboard sides of the watercraft when supported by the watercraft support in the raised support position. 36. The watercraft lift of claim 34 wherein the securing member is attached to the frame at a location lower than the bow of the watercraft and below the water line when the watercraft is positioned on the watercraft support with the watercraft support in the lowered support position and the watercraft lift positioned in the body of water. 37. The watercraft lift of claim 34 wherein the cover is wound about the roller in a first rotational direction when the upper end portions of the port and starboard arms are in the forward position, the cover having a port side pocket extending along an edge portion of the port side portion and a starboard side pocket extending along an edge portion of the starboard side portion, and the watercraft lift further includes an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member having a port side portion extending through the port side pocket of the cover and terminating in an end portion and a starboard side portion extending through the starboard side pocket of the cover and terminating is an end portion, the end portions of the port and starboard side portions of the perimeter member being attached to the roller, the length of the port and starboard side portions being sized such that as the cover is unwound from the roller as the upper end portions of the port and starboard arms are moved from the forward position to the rearward position and the port and starboard arms approach the rearward position, the end portions of the port and starboard side portions of the perimeter member are wound about the roller in a second rotational direction opposite the first rotational direction sufficient to stretch the port and starboard side portions of the perimeter member into a taut state such that the taut port and starboard side portions of the perimeter member apply downward force along the length of the port and starboard edge portions of the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard arms are moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 38. The watercraft lift of claim 34 wherein the cover is wound about the roller in a first rotational direction when the upper end portions of the port and starboard arms are in the forward position, and the watercraft lift further includes an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member having a port side portion attached to the edge portion of the port side portion of the cover and terminating in an end portion and a starboard side portion attached to the edge portion of the starboard side portion of the cover and terminating is an end portion, the end portions of the port and starboard side portions of the perimeter member being attached to the roller, the length of the port and starboard side portions being sized such that as the cover is unwound from the roller as the upper end portions of the port and starboard arms are moved from the forward position to the rearward position and the port and starboard arms approach the rearward position, the end portions of the port and starboard side portions of the perimeter member are wound about the roller in a second rotational direction opposite the first rotational direction sufficient to stretch the port and starboard side portions of the perimeter member into a taut state such that the taut port and starboard side portions of the perimeter member apply downward force along the length of the port and starboard edge portions of the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard arms are moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 39. The watercraft lift of claim 34 further including an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member being attached to port and starboard side portions of the cover and terminating in port and starboard end portions attached to the roller, the perimeter member being sized in length such that as the cover is unwound from the roller as the upper end portions of the port and starboard arms are moved from the forward position to the rearward position and the port and starboard arms approach the rearward position, the perimeter member is stretched into a taut state such that the taut the perimeter member applies downward force to the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard arms are moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 40. The watercraft lift of claim 34 wherein the second attachment member is elastic and the length of the elastic second attachment member is sized such that as the port and starboard arms approach the rearward position, the elastic second attachment member is stretched sufficiently to apply a rearward force on the rearward end portion of the cover sufficient to place the cover in a taut state. 41. The watercraft lift of claim 40 further including an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member being attached to port and starboard side portions of the cover and terminating in port and starboard end portions attached to the roller, the perimeter member being sized in length such that as the cover is unwound from the roller as the upper end portions of the port and starboard arms are moved from the forward position to the rearward position and the port and starboard arms approach the rearward position, the perimeter member is stretched into a taut state such that the taut the perimeter member applies downward force to the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard arms are moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position. 42. The watercraft lift of claim 34 wherein the roller actuation member is a torsion spring operatively connected to the roller to apply a rotational force thereto as the upper end portions of the port and starboard arms are moved from the rearward position to the forward position, and wherein the cover is progressively wound about the roller and removed from covering the watercraft by the rotational force applied to the roller by the torsion spring as the upper end portions of the port and starboard arms are moved from the rearward position to the forward position when the watercraft is supported by the watercraft support in the raised support position. 43. The watercraft lift of claim 34 wherein the first attachment member is flexible. 44. The watercraft lift of claim 34 further including a spreader member extending between and spacing apart the port attachment member and the starboard attachment member at a position above the securing member. 45. The watercraft lift of claim 34 wherein the second attachment member is elastic with the length of the elastic second attachment member being sized such that as the port and starboard arms approach the rearward position, the elastic second attachment member is stretched sufficiently to apply a rearward force on the rearward end portion of the cover sufficient to place the cover in a taut state. 46. The watercraft lift of claim 45 further including an elongated and elastic perimeter member extending about a portion of the perimeter of the cover from a position toward the forward end portion of the cover to a position toward the rearward end portion of the cover, the perimeter member being attached to port and starboard side portions of the cover and terminating in port and starboard end portions attached to the roller, the perimeter member being sized in length such that as the cover is unwound from the roller as the upper end portions of the port and starboard arms are moved from the forward position to the rearward position and the port and starboard arms approach the rearward position, the perimeter member is stretched into a taut state such that the taut the perimeter member applies downward force to the port and starboard side portions of the cover to pull the cover downward over the watercraft as the upper end portions of the port and starboard arms are moved into the rearward position when the watercraft is supported by the watercraft support in the raised support position.