Abstract:
A boat lifting and stacking vehicle having a low profile frame, a carriage connected to a frame via a transverse I-beam track, a mast having a pair of forks protruding therefrom, and a hydraulic suspension system. The vehicle further includes an operating console that moves transversely and vertically with the carriage for enhanced operator visibility. Additionally, the vehicle does not require extra counterweights as the length of the frame and location of the engine equipment and fuel tanks provide adequate rotational balance for even the heaviest boat loads during the boat storage process. Moreover, the front wheel bases include a pair of deployable hydraulic cylinders that work in combination with the wheels as a weight distribution means. For proper loading and unloading alignment, a variety of steering options are available via the computer operated controls.

Description:
FIELD OF THE INVENTION 
       [0001]    The present disclosure relates to a boat storage vehicle. More particularly, the invention relates to a boat lifting and stacking vehicle having improved control, stability, and versatility. 
       BACKGROUND OF THE INVENTION 
       [0002]    Boat storage facilities continue to experience an increased demand in storage space due to an increase in boat ownership. Additionally, the shortage and high price of waterfront land increases the need for offshore boat storage facilities. These boat storage facilities are the equivalent of large warehouses. Boat storage facility owners endeavor to optimize storage and warehouse space in order to obtain a premium value from the purchased land. Thus, boats are stored on racks stretching horizontally throughout the storage facility. To maximize potential profitability and utilization of space, additional horizontal racks are stacked vertically. This multi-rack configuration is cost effective as more boats are stored in a smaller boat storage facility area footprint. Having the ability to consolidate the number of boats stored within a specific facility footprint reduces the need to purchase additional land to store more boats. The multi-rack configuration in the boat storage facilities are conventionally organized to include a plurality of pallet racks on which the boats are stored. 
         [0003]    Two sides of the boat storage facility having oppositely facing racks are typically separated by an aisle dimensioned to permit access to vehicles known as marina forklifts. The marina forklifts load and unload boats for storage. First, the boat is removed from the water by the marina forklift, then transported to the offshore boat storage facility, and lastly placed into one of the plurality of pallet racks where the boat is then stored for any given duration. Accordingly, minimizing the aisle space between two sides of the boat storage facility decreases the area required to store a comparable quantity of boats within a given boat storage facility footprint. Alternatively, decreasing the aisle width also potentially increases the quantity or size of boats stored in an existing boat storage facility footprint. The marina forklift must be able to freely maneuver in the aisle way separating the two sides of the boat storage facility in order to access any given pallet rack. Thus, control, stability, and versatility of the marina forklift is critical to the financial profitability of offshore boat storage facilities. 
         [0004]    Current marina forklifts utilize a set of forks protruding from a versatile mast located at one end of the vehicle. The forks are capable of engaging, lifting, and otherwise transporting a boat thereon. Most masts in the marina forklift industry are capable of obtaining both positive and negative lift relative to the ground or support level position. This enables the marina forklift to operate from the side of a loading platform rather than descent down a ramp toward water-level to perform a zero lift. From the side of the platform, the marina forklift forks are lowered to a negative lift position and placed underneath the hull of a boat to be lifted out of the water. The mast then raises the forks having the boat supported thereon to the support or ground level. The weight of the boat is balanced by a heavy counter-weight located near the backend of the marina forklift. This provides balance and stability to prevent the marina forklift from tipping forward. 
         [0005]    Increasing the lifting capacity, i.e. increasing the capacity to lift heavier or longer boats, of the marina forklift can be achieved by either shifting the counter-weight farther behind the front wheels or increasing the weight of the counter-weight. Under the first scenario, the marina forklift is longer. Under the second scenario, the marina forklift is heavier. Both situations create additional problems for boat storage facility owners. 
         [0006]    Increasing the length of the marina forklift effectively extends the area that the forklift requires for operation. The aisle separating the two sides of the boat storage facility must be increased to accommodate the extra length of the marina forklift plus any extra length of the boats. Increased aisle space decreases storage space. Decreasing storage space translates into less opportunity to return profits on a comparable marina boat storage facility. Due to the limited mobility of current marina forklifts, wide aisles are still required in order to properly orient boats for storage. 
         [0007]    Increasing the weight of the marina forklift also creates a host of other problems for marina boat storage facility owners. First, the marina platform floor must be designed to withstand the increased weight. Cracking of the cement flooring can be a problem if not properly reinforced. Stability of the marina forklift also becomes a concern as increased weight can cause reduction in stability, operation, maneuverability, and braking (especially downhill). Additionally, heavier marina forklifts require larger engines or higher performance engines in order to supply adequate horsepower to maintain requisite performance and capability. All of the aforesaid requirements add additional costs having an adverse effect to the bottom line of any marina boat facility owner. 
         [0008]    The marina forklift then transports the boat to the storage facility for storage. Marina forklifts may also incorporate a tandem lift cylinder system and chain in order to achieve the positive and negative lift positions. These devices are typically mounted between the mast uprights and may significantly limit driver forward visibility. Reduced visibility substantially limits the ability of the marina forklift operator to see, orient, and otherwise store the boat. Limited visibility while transporting the boat to the boat storage facility creates additional dangers for platform personnel and vehicles. Limited visibility enhances the potential for boat damage during the lifting, transporting and storing process. 
         [0009]    When in the storage facility, the marina forklifts raise the mast, forks, and boat thereon to a positive lift position to store the boat in any one of the plurality of storage racks. Marina forklift operators may also experience limited visibility when attempting to store boats in elevated storage racks. An operator located on the ground level may have difficulty seeing and locating a rack located several rows above ground level. 
         [0010]    Additionally, most current marina forklifts have complicated structures that require an intricate knowledge of complicated control functions. Complicated controls require that marina forklift operators receive extensive training before the marina forklift can be effectively and efficiently operated. The manipulation of multiple levers, controls, and buttons requires additional operator navigation time. The productivity of even a skillful operator is therefore sacrificed. Fully automated systems would relieve operators of these tedious tasks. 
         [0011]    Thus, there exists a significant need for an improved boat lifting and stacking vehicle that requires less maneuvering space when stacking boats in a storage facility. Such an improved boat lifting and stacking vehicle should not require a counterweight and should include a frame approximately the length of the largest stored boat, multidirectional steering capacities, an extendable and rotatable operator console, hydraulic supports to distribute forces exerted at the front and rear wheels, and improved operator controls. The present invention fulfills these needs and provides further related advantages. 
       SUMMARY OF THE INVENTION 
       [0012]    Herein disclosed is a specially designed boat lifting and stacking vehicle configured to be have improvements in control, stability, and versatility, over other forklifts and similarly configured vehicles. 
         [0013]    The above and other objects and the nature and advantages of the present invention will be more apparent from the following detailed description of certain specimens embodiments thereof, taken in conjunction with the drawing, wherein: 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The accompanying drawings illustrate the invention. In such drawings: 
           [0015]      FIG. 1  is a rear perspective view of a boat lifting and stacking vehicle having a raised mast; 
           [0016]      FIG. 2  is a rear perspective view of a boat lifting and stacking vehicle having a mast in a negative lift position; 
           [0017]      FIG. 3  is a rear perspective view of a boat lifting and stacking vehicle having a mast in a carry position; 
           [0018]      FIG. 4  is a front perspective view of a boat lifting and stacking vehicle having a mast in the free lift forward position; 
           [0019]      FIG. 5  is a front perspective view of a boat lifting and stacking vehicle in the forward drive position; 
           [0020]      FIG. 6  is a rear perspective view of a boat lifting and stacking vehicle having a raised mast and raised control seat via a scissors lift; 
           [0021]      FIG. 7  is a front perspective view of a boat lifting and stacking vehicle having a raised mast in the stacking position and a raised control seat via a scissors lift; 
           [0022]      FIG. 8  is a bottom view of a boat lifting and stacking vehicle carrying a boat in the crab steer position; 
           [0023]      FIG. 9  is a bottom view of a boat lifting and stacking vehicle carrying a boat in the side step steer position; 
           [0024]      FIG. 10  is a bottom view of a boat lifting and stacking vehicle carrying a boat in the circle steer position; 
           [0025]      FIG. 11  is a bottom view of a boat lifting and stacking vehicle carrying a boat in the radius steer position; 
           [0026]      FIG. 12  is a bottom view of a boat lifting and stacking vehicle carrying a boat in the standard rear steer position; 
           [0027]      FIG. 13  is a side view of a boat lifting and stacking vehicle having a hydraulic cylinder as incorporated into the front and rear wheels; 
           [0028]      FIG. 14  is a side view of a boat lifting and stacking vehicle suspension in depressed and lifted positions; 
           [0029]      FIG. 15  is a 
           [0030]      FIG. 16  is an outside perspective view of a boat lifting and stacking vehicle wheel bridge; 
           [0031]      FIG. 17  is a side view of a boat lifting and stacking vehicle wheel bridge; 
           [0032]      FIG. 18  is a top view of a boat lifting and stacking vehicle wheel bridge; 
           [0033]      FIG. 19  is a front view of a boat lifting and stacking vehicle wheel bridge; and 
           [0034]      FIG. 20  is an inside perspective view of a boat lifting and stacking vehicle wheel bridge. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    As shown in the exemplary drawings for purposes of illustration, the present disclosure for the boat lifting and stacking vehicle is referred to generally by the reference number  100 . Turning now to the representative figures in the specification,  FIG. 1  illustrates the boat lifting and stacking vehicle  100  in a rear perspective view having mast  102  with a raised carriage  104  and forks  106 . The vehicle  100  operates similar to a conventional marina forklift or crane in many ways, except that vehicle  100  is capable of lifting and stacking longer boats in buildings with narrower aisles. Additionally, vehicle  100  of the present disclosure can better rack full length boats in the end racks. This provides the marina owner with the opportunity to maximize income for a given facility layout. As will be shown in the proceeding illustrations, the vehicle  100  is illustrated without cargo so as to better disclose the subject matter. 
         [0036]    The marina forklift or vehicle  10   c  of the present disclosure does not require a counterweight when lifting boats. The lightweight frame  108  of the vehicle  100  should be approximately ten feet longer than the longest boat that needs to be stored. By placing the majority of the equipment (i.e. engines, fuel tanks, etc.) near the rear  110  of the vehicle  100 , this weight, in combination with the length of the frame  108  provides for adequate balancing of any moment exerted on the forks  106  that protrude away from the mast  102 . Thus, the vehicle  108  is lightweight when compared to other types of marina forklifts. 
         [0037]    As with conventional marina forklifts or cranes, the vehicle  100  is able to drive up to the side of a seawall for retrieving boats from the water with the mast  102 , carriage  104 , and forks  106  in the negative lift position ( FIG. 2 ). The negative lift position is particularly useful for lifting boats out of the water as the vehicle  100  is able to reach below the underside of a boat hull to secure transportation via the two forks  106  that protrude out from the mast  102  of the vehicle  100 . The mast  102  is then raised ( FIG. 4 ) until the bottom of the boat hull is completely removed from the threshold water level. Once in this position, the boat may be transported about the marina platform and into the storage facility. 
         [0038]    The vehicle  100  uses its own frame  108  as a counterweight to counteract the large loads exerted at the end of the mast  102  and on the forklift forks  106 . The forks  106  are any that are well known in the art. It is conceived that additional weights could be placed at the rear  110  of vehicle  100 , but as it will become clear from this specification, the weight advantages of the present disclosure offer significant advantages over the prior art. A sturdy I-beam rail  112  configuration is used to reinforce and stabilize the vehicle  100  to ensure that the vehicle  100  can raise even the largest boats. 
         [0039]    The frame  108  itself is a structural box having an integral I-beam rail  112  welded along the inside surface of the frame  108 . Integral hydraulic tanks  114  line each main frame  108  section on the left  108   a  and right  108   b  sides of the vehicle  100  with suction and return directly under a pump and valve manifold, respectively. Each frame section  108   a ,  108   b  supports one engine  116  and a fuel tank  118 . These devices are placed substantially at the rear  110  of the vehicle  100  as the only counterweight required to support the rotational forces exerted via a moment arm created by the boat over the forks  106  and mast  102 . A cable management system (not shown) is carried by one side of the frame  108   a ,  108   b  and feeds signal wires between the frame  108  and the traverse carriage  104 . A removable (for shipping) rear cross member  120  provides torsional structural support between the two I-beam frame sections  108   a ,  108   b . A set of removable structural tubes  122  called cross members hold the frame  108  spacing constant and provide additional torsional stiffness to the frame sections  108   a ,  108   b . A shorter set of cross members (not shown) also hold the two frame sections close together for shipping. 
         [0040]    On the outside of the frame  108 , a series of frame support stairs and rails  124  are mounted from the ground to the top of the wheel support bridges  126  to allow access to the operator console  128 .  FIGS. 13-20  illustrate the wheel support structures  126  that bridge a wheel well  130  in the sides of the frame  108 . These structures  126  also enable each wheel  132  to turn perpendicular to the frame  108  ( FIG. 9 ). As specifically disclosed in  FIG. 14 , the wheel support  126  covers a series of components that regulate wheel  132  turn and the vehicle  100  suspension. 
         [0041]      FIG. 14  illustrates a detailed view of the wheel support structure  126 . A series of multidirectional steering mechanisms (not shown) are configured into the vehicle&#39;s  100  computer system (not shown) for enhanced mobility. The configuration of the wheel support bridges  126  enables 180 degree rotation of the wheels  132  such that the vehicle  100  is capable of engaging in circle steer, crab steer, and side steer, as described below. With these enhanced steering mechanisms, boat storage owners can build storage warehouses with smaller aisles for the marina forklift  100 . Furthermore, stacking boats on end racks is simplified when in side steer because the marina forklift  100  of the present disclosure is capable of moving laterally when in side steer. The wheel  132  is connected to a drive motor, gear box, and drive system (not shown). The wheel  132  is mechanically coupled to the wheel support  126  by an L-shaped support beam  134 . Movement of the L-shaped support beam  134  is regulated by a rotatable shaft mechanism  136 . The shaft mechanism  136  along with wheel steer (not shown) and drive support systems (not shown) maintain tire orientation and enable 180 degrees of steering. The internal computer system of the vehicle  100  regulates the shaft mechanism  136  to obtain the different steering positions as herein disclosed. 
         [0042]    The width of the tire well  130  must be wide enough to enable unrestricted rolling motion of the tire  132  when turned perpendicular to the frame  108  of the vehicle  100  (i.e. a 90 degree rotation). The structural members of the wheel support  126  are run though a vertical plate that connects to the frame  108  by a five studded plate  138 . The wheel support structures  126  also support the wheel brake (not shown) and gearbox drive system (not shown). 
         [0043]    Further illustrated in  FIG. 14  is a support bar  140  that is mechanically coupled to a hydraulic suspension system  142  (also  FIG. 36 ). When the vehicle  100  traverses across a plane, such as a marina platform, the wheel support bar  140  of the disclosed suspension system  142  is capable of absorbing upward and downward movement. The suspension system  142  rotates around a center of rotation located at the pin  144  adjacent the support bridge  126 . The downward and upward movement of the hydraulic suspension system  142  is transferred to the L-shaped support beam  134  and other components.  FIG. 14  illustrates these parts being slightly displaced from equilibrium. It is conceived that only one such suspension system  142  is required to properly relieve the stresses exerted on the frame  108  of the vehicle  100  when transporting heavy loads across a marina platform (i.e. the suspension system  142  need only be incorporated into one wheel support bridge  126 ). Although, the disclosed suspension system  142  could be incorporated into every wheel support bridge  126 . 
         [0044]    Further incorporated into the wheel support structures  126  are bearings and structures to react to loads from the wheels  132 . A pair of hydraulic supports  146  are incorporated into the front two wheel support bridges  126 . When placing a boat in a rack, significant forces are exerted on the front  111  of the vehicle  100 . Before deployment of the hydraulic supports  146 , all of the frontal forces are exerted via the two contact points of the two front wheels  132 . The deployment of the hydraulic supports is not intended to eliminate the wheels  132  as a contact point. Rather, the hydraulic supports  146  help distribute the frontal forces over a larger surface area. Thus, better force distribution alleviates the need for strong reinforced concrete floors. Front wheel loads are displaced by a pair of hydraulic supports  146 . When either loading or unloading, the hydraulic supports  146  are deployed ( FIG. 13 ) such that the impact pressure at the front wheels  132  is displaced through the hydraulic supports  146 . The hydraulic supports  146  are not meant to eliminate the loads being exerted on the wheels  132 , but rather redirect and displace those loads. When deployed, the hydraulic supports  146  effectively displace wheel forces over a broader area. Accordingly, approximately thirty percent less concrete (14 to 16 inches compared to 24 inches in one case) reinforcement is required to support the vehicle  100  during the loading or unloading process. 
         [0045]    After lifting the boat to a point where the keel and props clear the cross members  122  of the frame  108 , the carriage  104  retracts and brings the boat over the frame  108  ( FIG. 5 ) (boat not shown). The carriage  104  supports the combined mast/fork system  102 / 106 , tilt cylinders (not shown), operator console  128 , a third engine  148 , fuel tank  150 , and hydraulic tanks  152 . Tilt cylinders (not shown) are mounted high on lightweight, but strong tilt towers (not shown), due to the short length of the tilt cylinders (not shown) themselves. The traverse carriage  104  is as long as possible to reduce loads, yet short enough to allow overall length of the vehicle  100  to extend only ten feet longer than the longest boat it carries. As presently disclosed, no additional counterweights are needed to support the frame  108  from tipping when the two frame engines  116  and two frame fuel tanks  118  are located near the rear of the vehicle  100 . Thus, the overall length of the vehicle  100  is comparatively short—only approximately ten feet longer than the longest boat endeavored to be stored. A drive system (not shown) controls the speed and location of the traverse carriage such that rollers (not shown) in the rear and bearing pads (not shown) in the front optimize performance. 
         [0046]    The traverse carriage  104  then secures the boat to the rear of the frame  108  for transporting a boat across a marina platform. As shown in  FIGS. 3 ,  4  and  7 , the operator console  128  moves along the frame  108  of the vehicle  100  with the traverse carriage  104 . During the process of loading and unloading, the operator, located in the operator console  128 , has a better and closer view of the boat and its position in relation to the forks  106  of the vehicle  100 , thus providing optimum visibility. 
         [0047]    The vehicle  100  incorporates a moveable operator console  128 . During loading and unloading, the operator console  128  moves with the traverse carriage  104 . Additionally, when the vehicle  100  is transporting boats across a marina platform, the operator console  128  is capable of 180 degree rotation, such that the operator has an unobstructed view, as described herein. Moreover, the operator console  128  is also capable of moving vertically with the mast  102  when boat storage and placement requires stacking, as described herein. Thus, the operator has better visibility when transporting and stacking the boats. 
         [0048]    After the boat cargo is secured to the rear of the frame  108 , the operator console  128  is capable of rotating 180 degrees. Thus, the operator console of the present disclosure has two modes: (1) facing the boat for seawall operations ( FIG. 1 ) and racking ( FIG. 6 ); and (2) facing the away from the boat for unobstructed driving visibility ( FIG. 5 ). Additionally, the operator console  128  elevates up to half the lift height of the mast  102  to maximize visibility during stacking or warehousing ( FIG. 6 ). A scissors lift  154  or other suitable lifting or raising mechanism in the art may be used to perform elevation of the operator console  128 . Operator console lift position may be governed by the internal computer system program to react to raising of the mast  102 . Alternatively, the operator may have separate controls to raise or lower the console  128  independent of the mast  102 . Furthermore, the operator console  128  contains operator controls for engines, drive systems, and the lift systems. 
         [0049]    A variety of electronics and controls regulate the mechanical operations of the vehicle  100 . The vehicle  100  uses a CAN bus instrumentation and control system for the engines, hydrostatic drive, traverse carriage drive, steering, and stability control. Sensors include speed pedal, brake pedal, hydraulic function pressures, temperatures, distance/location, rotation angle encoders, and locking mechanism indicators. Control algorithms include engine/pump speeds, steering modes (front wheel steer, rear wheel steer, 4 wheel radius steer, crab steer, Side Step steer, and circle steer), stability, Drive Mode, Rack Mode, Park and Place Mode, Idle Mode, Start, Shutdown, Diagnostics, and Maintenance. Furthermore, the control algorithms are capable of engaging the wheels in four by four movement. 
         [0050]    Once the operator console  128  is in the drive position (i.e., facing away from the boat), the operator may drive the vehicle  100  across the marina platform to the storage facility. While driving, the tire loads on the concrete are nearly half those of a traditional marina forklift or crane. This is due to the unique lightweight design of the vehicle  100  and absence of counterweights found in current marina forklift designs. The combination of the overall length of the frame  108 , being only approximately ten feet longer than the largest boat, and the balancing loads of the operating equipment (rear engines, rear pumps, intake filter muffler, etc) alone counter the forces exerted on the forks and transferred to the end of the mast  102  of the vehicle  100 . Counterweights are used on traditional marina forklifts or cranes to prevent the forklift or crane from tipping due to the large moment arms on the end of the forks. Since the frame  108  of the vehicle  100  is able to counter the moment arm of even the largest boat loads, additional weights are unneeded. Furthermore, while the frame  108  absorbs the majority of the distributed boat weight forces, the interior welded I-beams  112  provide relief as well. 
         [0051]    A stabilization system measures the weight and center of load, speed and amount of steering used, calculates acceptable speed and braking parameters to maintain stability under drive and steering conditions. This stabilization system also monitors the vehicle  100  when in Park and Place Mode, adjusts pressure of in-rigger cylinders that serve to spread the load when racking or lifting boats. Additionally, a set of hydraulics located on each wheel provides hydrostatic drive, lift and load sensors, controlled braking, steering function, suspension, and stability control. Each frame mounted engine  116  drives two pumps (not shown), one large load sense pump for the drive motors and one small fixed displacement pump for steering and accessory functions. The traverse carriage  104  mounted engine  148  drives a large load sense pump (not shown) for lifting, tilting, fork positioning, traverse carriage drive, and operator console lift. Additionally, a set of hydraulic tanks  114  on the frame  108  contain a divider and baffles (not shown) to maximize ambient cooling by routing oil down one side, then down the other side of the divider. 
         [0052]    When driving along the platform to the storage facility, the vehicle  100  is in a rear turn drive position ( FIG. 5 ). Once inside the storage facility, the operator has the option of selecting from a variety of drive positions for precise alignment depending on the layout of the storage facility. Each of the following drive positions increase maneuverability so that facility owners may build smaller aisles and drive spaces, while increasing storage space. Such steering positions might include side step steer ( FIG. 9 ), crab steer ( FIG. 8 ), circle steer ( FIG. 10 ), radius steer ( FIG. 11 ), or standard rear steer ( FIG. 12 ). In circle steer, the vehicle  100  turns around its own center. Additionally the side step steer allows the vehicle  100  to move perpendicular to the direction of the storage racks. This provides a mechanism to precisely align and place boats on racks—especially end racks. Boat storage facility owners can build storage warehouses having aisles slightly larger than the overall width of the vehicle  100 , when equipped with the array of steering mechanisms as disclosed herein. 
         [0053]    Once the vehicle  100  having a boat thereon is lined up with the intended storage bay, the mast  102  and forks  106  carrying the boat are raised (see  FIG. 6 ). As further shown in  FIG. 6 , the operator console  128  is also raised with the mast  102 . Presently, it is conceived that the operator console  128  will be raised by a scissors lift  154  ( FIG. 6 ), although any suitable lifting mechanism in the art could be integrated into the vehicle  100 . At the elevated position disclosed in  FIG. 6 , the operator has improved visibility of the storage rack, bottom of the boat, and relative fork placement. 
         [0054]    Once the boat is aligned with the proper storage bay, the operator selects Park and Place Mode, which allows the traverse carriage to move the boat forward into the rack bunk ( FIG. 7 ). Again, the design of the vehicle  100  reduces the floor or aisle space required to place the boat in a rack because the mast  102  is able to traverse from the position shown in  FIG. 6  to the extended position shown in  FIG. 7 . When in the extended position shown in  FIG. 7  the boat (not shown) on the forks would effectively be located in the storage bay. The rest of the vehicle  100  would be aligned in the aisle. It is conceived, therefore, that the aisle need only be approximately the length of the boat plus 10 feet. The operator console  128  is shown in a raised position to give the operator a better view when placing the boat in the storage rack (also not shown). 
         [0055]    An active stability control system integrated into the computer system ensures that the operator can concentrate on the safe placement of the boat into the rack. Hydraulic load supports  146  ( FIG. 13 ) extend from the front of the frame  108  to the bridge support  126  to reduce tire loading on the concrete and also increases the solid feel during side shift. Such hydraulic load supports  146  may be included on any or all of the bridge supports  126 . The racking cycle is complete when the traverse carriage  104  returns to the position depicted in  FIG. 5  with the mast  102 , forks  106 , and operator console  128  retuned to the lower, drive positions. 
         [0056]    Furthermore, vehicle  100  also features four wheel hydrostatic drive, digital hydraulics, in-rigger cylinders, and other lift and stability sensors in order to rack boats using smaller aisles. Thus, marina owners are capable of storing larger numbers of longer boats on higher racks in smaller building footprints 
         [0057]    A variety of modifications and improvements to the boat lifting and stacking vehicle of the present disclosure will be apparent to those skilled in the art. Accordingly, those skilled in the art will appreciate that such changes may be made without departing from the underlying principles of the present disclosure. The above-described disclosure is not intended to limit the scope of the invention. Accordingly, the scope of the present invention is determined only by the following claims.