INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 61/790,904 filed on March 15, 2013, entitled "ELECTRIC OUTBOARD PROPULSION SYSTEM," which is hereby incorporated by reference in its entirety.

BACKGROUND

Field of the Invention

[0002] The present invention relates to watercraft propulsion. More specifically, the invention relates to lightweight electric outboard motors used to inflate, deflate, and propel an inflatable watercraft.

Description of the Related Art

[0003] Watercrafts are used around the world for various purposes including, transportation, fishing, recreation, and/or living spaces. Watercrafts can be motorized or non-motorized. Some watercrafts can be fitted with separate motor assemblies, for example, an outboard motor, to provide motorized propulsion capability to an otherwise non- motorized vessel. Other watercrafts can be constructed with one or more in-board motors. Also, some watercrafts, including sailboats, rowboats, kayaks, and canoes, may be used primarily without motors.

SUMMARY

[0004] The devices, systems, and methods disclosed herein have several features, no single one of which is solely responsible for its desirable attributes. Without limiting the scope as expressed by the claims that follow, its more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled "Detailed Description of the Preferred Embodiments" one will understand how the features of the system and methods provide several advantages over traditional systems and methods.

[0005] The subject matter disclosed herein relates to a device containing an electric motor that may be mounted to the transom of a watercraft. The device may contain one or more batteries to power the electric motor. The electric motor may be coupled to a drive shaft. The drive shaft may be coupled to a propeller and/or impeller. The electric motor may rotate the drive shaft and in turn, rotate the propeller and/or impeller. A rotating impeller may be positioned within a flow path. The rotating impeller may draw water into one end of the flow path and eject water from the other end to provide propulsion to the watercraft that the device is mounted to. In some embodiments, the water is ejected from the flow path and at least partially into the air. The device may include a rudder and may further include a tiller. In this way, the tiller may be used to rotate the device and/or rudder with respect to the watercraft in order to steer and maneuver the watercraft. The device may also include an electric air pump. The electric air pump may be powered by the one or more batteries. The air pump may be driven by the same electric motor that is coupled to the drive shaft or the air pump may employ a separate electric motor. The air pump may be configured to inflate and/or deflate an inflatable watercraft. The configurations described below allow for a light weight, environmental friendly, high performance device for propelling a watercraft. In particular, the device may be used to inflate and propel and maneuver an inflatable watercraft. The device may be especially useful in emergency situations.

[0006] One innovative aspect of the subject matter described in this disclosure is an electric outboard drive configured to be mounted to a transom of a watercraft. The drive may include a rudder body having a flow path therethrough. The flow path may have an intake and an exit nozzle. An electric motor may be disposed within the rudder body and configured to rotate a drive shaft coupled to the electric motor. A propeller and/or impeller may be coupled to the drive shaft and disposed within the flow path. An air pump may also be disposed within the rudder body.

[0007] In some aspects, an electric outboard drive is configured to be mounted to a transom of a watercraft. The electric outboard drive may include a rudder body having a flow path therethrough. The flow path may include an intake and an exit. An electric motor may be disposed within the rudder body and may be configured to rotate a drive shaft coupled to the electric motor. An impeller may be coupled to the drive shaft and disposed within the flow path. An air pump may be disposed within the rudder body. The flow path exit may be positioned above the waterline when the electric outboard drive is mounted to a transom of a watercraft. The electric motor may be mechanically coupled to the air pump. In some embodiments, the electric motor is mechanically coupled to the air pump with a drive belt. The drive shaft may positioned at an angle with respect to the longitudinal axis. The drive shaft may pass through a stuffing box. The stuffing box may partially function as a flow straightener. A flow straightener may be disposed aft of the impeller. The flow straightener may include a plurality of plates extending radially from the center of the impeller. A tiller may be coupled to the rudder body. One or more batteries may be disposed within the rudder body. A motor controller may be disposed within the rudder body. The batteries may comprise rechargeable lithium ion batteries.

[0008] These and other features, aspects, and advantages of the invention disclosed herein are described below with reference to the drawings of certain embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The illustrated embodiments of a propulsion system and components are intended to illustrate but not to limit the invention. Additionally, from figure to figure, the same reference numerals have been used to designate the same components of an illustrated embodiment. It is to be noted that the figures provided herein are not drawn to any particular proportion or scale, and that many variations can be made to the illustrated embodiments. The following is a brief description of each of the drawings.

[0010] FIG. 1 is a schematic perspective view of an outboard motor drive according to one embodiment.

[0011] FIG. 2 is a cross-sectional view of the outboard motor drive of FIG. 1.

[0012] FIG. 3 is an enlarged view of the electric motor, impeller, and flow straightener of the outboard motor drive of FIG. 1.

[0013] FIGS. 4-5 are perspective views of the outboard motor drive of FIG. 1.

[0014] FIG. 6 is a front view of the outboard motor drive of FIG. 1.

[0015] FIG. 7 is a side view of the outboard motor drive of FIG. 1.

[0016] FIG. 8 is a rear view of the outboard motor drive of FIG. 1.

[0017] FIG. 9 is a top view of the outboard motor drive of FIG. 1.

[0018] FIG. 10 is a bottom view of the outboard motor drive of FIG. 1.

[0019] FIG. 1 1 is a schematic perspective view of an outboard motor drive according to another embodiment having a flexible drive shaft, a bottom intake, and a nozzle positioned above the intake. [0020] FIG. 12 is a cross-sectional view of the outboard motor drive of FIG. 1 1.

[0021] FIG. 13 is an enlarged view of the electric motor, impeller, and flow straightener of the outboard motor drive of FIG. 1 1.

[0022] FIGS. 14-15 are perspective views of the outboard motor drive of FIG.

1 1.

[0023] FIG. 16 is a front view of the outboard motor drive of FIG. 1 1.

[0024] FIG. 17 is a side view of the outboard motor drive of FIG. 1 1.

[0025] FIG. 18 is a rear view of the outboard motor drive of FIG. 1 1.

[0026] FIG. 19 is a top view of the outboard motor drive of FIG. 1 1.

[0027] FIG. 20 is a bottom view of the outboard motor drive of FIG. 1 1.

[0028] FIG. 21 is a schematic perspective view of an outboard motor drive according to another embodiment having a straight drive shaft positioned at an angle and an air pump coupled to the electric motor.

[0029] FIG. 22 is a cross-sectional view of the outboard motor drive of FIG. 21.

[0030] FIGS. 23-24 are perspective views of the outboard motor drive of FIG.

[0031] FIG. 25 is a front view of the outboard motor drive of FIG. 21.

[0032] FIG. 26 is a side view of the outboard motor drive of FIG. 21.

[0033] FIG. 27 is a rear view of the outboard motor drive of FIG. 21.

[0034] FIG. 28 is a top view of the outboard motor drive of FIG. 21.

[0035] FIG. 29 is a bottom view of the outboard motor drive of FIG. 21.

[0036] FIG. 30 is a schematic perspective view of an outboard motor drive according to another embodiment similar to the embodiment shown in FIG. 21

[0037] FIG. 31 is a cross-sectional view of the outboard motor drive of FIG. 30.

[0038] FIGS. 32-33 are perspective views of the outboard motor drive of FIG.

30.

[0039] FIG. 34 is a front view of the outboard motor drive of FIG. 30.

[0040] FIG. 35 is a side view of the outboard motor drive of FIG. 30.

[0041] FIG. 36 is a rear view of the outboard motor drive of FIG. 30.

[0042] FIG. 37 is a top view of the outboard motor drive of FIG. 30. [0043] FIG. 38 is a bottom view of the outboard motor drive of FIG. 30.

[0044] FIG. 39 is a perspective view of the outboard motor drive of FIG. 30 along with a un-inflated inflatable watercraft.

[0045] FIG. 40 is a perspective view of the outboard motor drive of FIG. 30 mounted to the transom of an inflated inflatable watercraft.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] The following description and examples illustrate preferred embodiments of the present invention. It does not set forth all embodiments. More specifically, the following embodiments relate a removable outboard motor drive. The outboard motor drive may be releasably attached to a transom of a watercraft. The outboard motor may be attached to a transom such that the motor may be rotated about the longitudinal, lateral and/or transverse direction with respect to the transom. The outboard motor drive may include a tiller that can be configured to be held in the hand of a user. Manipulation of the tiller may in turn manipulate the position of the outboard motor. The outboard motor drive may include a housing that may be used as a steering rudder for a watercraft. The housing may include one or more batteries, one or more electric motors, and one or more impellers. In some embodiments, the outboard motor drive is configured to expel water above the waterline in which the drive is submerged into. In this way, water may be expelled at least partially into the air and towards the rear of the motor drive thus providing forward propulsion to a watercraft.

[0047] The following description and the accompanying figures, which describe and show the preferred embodiments, are made to demonstrate several possible configurations that a watercraft propulsion system can take to include the various disclosed aspects and features. Various aspects will now be described with reference to specific forms or embodiments selected for purposes of illustration. It will be appreciated that the spirit and scope of the disclosed motor drives are not limited to the selected forms explicitly disclosed herein. For example, while the embodiments disclosed herein are shown and described in connection with an inflatable raft or dinghy, it is understood that the propulsion system of the present invention may be adapted for use with any suitable watercraft including, for example, skiffs, life rafts, tenders, sail boards, surfboards, stand up paddle boards ("SUP boards"), kayaks, sailboats, and the like. [0048] Traditionally, smaller watercrafts have been used in conjunction with larger watercrafts in emergency situations and/or to transfer passengers or equipment to and from the larger watercraft. For example, inflatable watercrafts, rigid-hulled inflatable boats, dinghies, life rafts, or tenders may be used to evacuate passengers safely from a larger watercraft and/or to transport passengers from the larger watercraft to a dock, or another large watercraft, in a marina or other setting. Smaller watercrafts may also be used for fishing, diving, and/or recreation. Often, such watercrafts are propelled through the water by an outboard gasoline powered engine mounted to the transom.

[0049] The general purpose the embodiments described herein is to provide an outboard motor design for watercrafts. The outboard motor drive may include an electric motor powered by one or more batteries. The electric motor may rotate a driveshaft coupled a impeller. The electric motor may provide enough force to propel the boat to speeds comparable to a gasoline engine.

[0050] The preferred embodiments advantageously provide a propulsion system for a watercraft. The system may be used in shallow water. The system may have zero emissions. In some embodiments, the system may assist in the catching of waves by providing additional speed to a watercraft when attempting to catch a wave. In some embodiments, the system may be used to steer and/or propel the watercraft. In some embodiments the propulsion system is stored in conjunction with an inflatable life raft. The propulsion system may include an air pump to inflate the life raft. The propulsion system may then be mounted to the life raft and used to propel the raft. The propulsion system may include one or more solar panels. The solar panels may help to ensure that the propulsion system has sufficient battery charge to inflate the life raft and/or propel the watercraft.

[0051] Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. The outboard drives systems disclosed herein may be more environmental friendly than traditional gas engines which may emit toxins and/or pollutants into the air and water. In some aspects, the system disclosed herein may be safer for swimmers and marine life because the impeller is covered and/or enclosed within a rudder body. Furthermore, an enclosed impeller may also help prevent the impeller from being entangled by, for example, rope, or kelp. In some embodiments, the system is configured to operate in shallow waters and propel a watercraft at a high rate of speed. In some embodiments, the systems disclosed herein are lightweight and configured to be attached to a variety of watercraft. In some embodiments, the outboard motor drive system includes a tiller and/or is shaped to function as a rudder. In some embodiments, the system includes one or more batteries. The batteries may be rechargeable.

[0052] In some advantageous embodiments, the systems disclosed herein can incorporate a battery powered motor module. The motor module can be used to propel the watercraft, inflate the watercraft, and/or deflate the watercraft. In some embodiments, the inflatable watercraft does not require a separate motor for propulsion and/or a separate pump for inflation and/or deflation. In other embodiments, the battery powered motor module is configured to propel the watercraft and power a separate air pump for inflating and/or deflating an inflatable watercraft. In some advantageous embodiments, the systems disclosed herein may be used in an emergency to both rapidly inflate a life-raft and provide thrust to propel the life-raft to safety. For example, the system may be stored with an inflatable craft in a small space, for example a storage area on a boat or the trunk of a car without fear of leaking gasoline, and easily accessed, inflated, and propelled.

[0053] As used herein, the singular forms "a," "an," and "the" include both singular and plural referents unless the context clearly dictates otherwise. The terms "comprising," "comprises" and "comprised of as used herein are synonymous with "including," "includes" or "containing," "contains," and are inclusive of open-ended and do not exclude additional, non-recited members, elements or method steps. The terms "comprising," "comprises," and "comprised of when referring to recite components, elements or method steps also include embodiments which "consist of said recited components, elements or method steps. Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order, unless specified. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0054] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the features of the claimed embodiments can be used in any combination.

[0055] To assist in the description of these components of the securement system, the following coordinate terms are used (see, e.g., FIGS. 1, 1 1, 21 , and 30). A "lateral axis" is generally parallel to the tiller and runs from the front of the device to the rear of the device. A "longitudinal axis" is normal to the lateral axis and runs from the bottom of the device to the top of the device. A "transverse axis" extends normal to both the longitudinal and lateral axes. In addition, as used herein, "the longitudinal direction" refers to a direction substantially parallel to the longitudinal axis; "the lateral direction" refers to a direction substantially parallel to the lateral axis; and "the transverse direction" refers to a direction substantially parallel to the transverse axis.

[0056] Nautical terms used herein are commonly used to describe watercraft, are well known in the art, and are used consistently throughout this description. For example, "stern" is used in reference to a rear portion of a watercraft while "bow" is used in reference to a front portion. In addition, "aft" refers to the direction towards the stern and "fore" or "forward" refers to the direction towards the bow. "Starboard" refers to the direction towards the right-hand side of the vessel facing forward while "port" refers to the direction towards the right-hand side of the vessel facing forward. Terms such as "upper," "lower," "top," "bottom," "underside," "upperside," and the like, are used to describe the present propulsion system, and are used in reference to the illustrated orientation of the embodiment.

[0057] The following figures and associated discussion describe and illustrate several embodiments of an outboard drive system for use with a variety of other watercraft. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner, simply because it is being utilized in conjunction with a detailed description of certain specific embodiments disclosed herein. Furthermore, embodiments disclosed herein may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to the embodiments herein described. To facilitate a complete understanding of the embodiments, the remainder of the detailed description describes the invention with reference to the figures; wherein like elements among the embodiments are referenced with like numerals throughout the following description.

[0058] FIGS. 1-2 illustrate an outboard drive system 100 according to one embodiment. As shown, the outboard drive system 100 includes a rudder body 1 10 and a tiller 105. The tiller 105 may be used to rotate the rudder body 1 10 with respect to a watercraft to which the dive system is attached to. The outboard drive system 100 can be configured to be attached to the stern of a watercraft. The outboard drive system 100 may be removably attached such that the outboard drive system 100 may be used with more than one watercraft. The outboard drive system 100 may be configured to be attached to a watercraft such that the outboard drive system 100 may be rotated and or moved about the lateral, longitudinal, and/or transverse direction.

[0059] Continuing with FIGS. 1-2, a rudder body 1 10 includes an electric motor 120 coupled to a drive shaft 150. The electric motor 120 is configured to rotate the drive shaft 150. The drive shaft 150 is coupled to an impeller 160. The impeller 160 is disposed within a flow path 180 than includes a water intake 170 and an exit and/or nozzle 175. The water intake 170 may be covered by a grate (not shown) and or include a plurality if intake openings 172. In this way, the grate and/or intake openings can reduce the likelihood that an object is drawn into the flow path because such objects may damage and/or interfere with the impeller and its rotation. A flow straightener or diffuser 165 may be disposed within the flow path 180. As illustrated, the flow straightener 165 is positioned aft of the impeller 160. The flow straightener 165 can increase the efficiency of the water jet by directing the water outflow into a more laminar flow. In operation, rotation of the impeller 160 draws water into the intake 170 and out of the exit 175 to provide forward thrust. [0060] As shown in FIGS. 1-2, the flow path 180 includes an inlet 170 located generally on the stern side of the rudder body 1 10 and an outlet 175 located generally on the aft side of the rudder body. One or more batteries 101 may be enclosed within the rudder body 1 10. The batteries 101 may power the electric motor 120. In some embodiments, one or more batteries 101 are located on the watercraft and are electronically connected to the electric motor 120. The batteries 101 may be rechargeable. The rudder body and/or tiller may include an electric charging port for connecting the batteries 101 and/or electric motor 120 to a power source. The rudder body may also include an electric pump configured to inflate and/or deflate an inflatable watercraft. A motor controller 109 may be coupled to the batteries 101 and/or the electric motor 120.

[0061] Turning to FIG. 3, bevel gears 190 may be used to couple the driveshaft 150 to the propeller 160 in order to transfer the rotational movement of the driveshaft 150 about the longitudinal axis to rotational movement about the lateral axis in order to rotate the impeller 160. The drive shaft 150 may pass through a stuffing box 155 configured to prevent water ingress into the rudder body 1 10. The flow straightener 165 comprises one or more this plates positioned aft of the impeller 160. As shown in FIG. 3, the flow straightener 165 includes four radially extending plates with the plates intersecting at roughly the center of the impeller 160. FIGS. 4-10 show additional views of the outboard drive system 100.

[0062] FIG. 1 1 illustrates an outboard drive system 200 according to another embodiment. This embodiment is similar to the embodiment shown in FIGS. 2-10. However, unlike the outboard drive system of FIG. 1 , the system of FIG. 1 1 is configured to expel water from a first position below the water line to a second position above the water line. As such, water may be drawn in from beneath the hull of a watercraft, where it passes through one or more impellers 160 which increase the velocity of the water flow through the flow path. The water may then exit the rudder through a nozzle 175 into the air (i.e. above the waterline) at high velocity, providing thrust to push the watercraft forward. As shown, inlet 170 comprises an opening on the aft and bottom of the rudder body 1 10. In use, the rudder body may be positioned such that the inlet 170 is below the surface of the water while the nozzle 175 is positioned above the surface of the water. Steering may accomplished by moving this nozzle 175 to either side of the watercraft. The tiller may be used to rotate the nozzle 175. [0063] Also shown in FIG. 1 1 , a curved, flexible drive shaft may be used rather than bevel gearing. In this way, less moving parts are utilized. The flexible drive shaft 250 may pass through stuffing box 255 configured to prevent water ingress into the rudder body 1 10. The stuffing box 255 may further comprise a flow straighter element 165. The flexible drive shaft 250, stuffing box 255, and flow straighter 165 are shown in more detail in FIG. 13.

[0064] Although not shown, the rudder body may include one or more batteries. The rudder body may also include an electric pump configured to inflate and/or deflate an inflatable watercraft. FIGS. 14-20 show additional views of the outboard drive system 200.

[0065] Turning to FIGS. 21-22, another embodiment of an outboard drive system 300 is illustrated. As shown, the electric motor 120, drive shaft 350, and impeller 160 are arranged in a generally straight line. In this way, no bevel gears are required and less power is lost. Thus, the system may operate more efficiently. Similar to the embodiment of FIGS. 1 1-20 above, water is drawn in from the bottom of the outboard drive system 300 and expelled above the water line. In addition, the electric motor 120 is coupled to an air pump 320 via a belt drive 310. As such, one electric motor can be used to inflate, deflate, and or propel an inflatable watercraft. In some embodiments, the propeller/impeller is disposed closer to the exit portion of the flow path 180 than shown in FIGS. 21-22. In this way, the intake 170 is further opened up such than more water can be drawn in and accelerated out. Furthermore, a drive shaft cover and/or stuffing box 355 may function as a flow straightener and/or diffuser adding further efficiencies and improving the overall performance. Although not shown, the rudder 1 10 body may include one or more batteries. The rudder body 1 10 may also include an electric pump configured to inflate and/or deflate an inflatable watercraft. FIGS. 23-29 show additional views of the outboard drive system 300.

[0066] FIGS. 30-31 illustrate another embodiment of an outboard drive system 400. The outboard drive system 400 is similar to outboard drive system 300. However, the outboard drive system 400 includes a more protracted or longer flow straightener 165. The outboard drive system 400 also includes a rudder body 1 10 having a rear notch 401. The rear notch 401 , in combination with the tiller 105 may be used to mount the drive system 400 to a watercraft. FIGS. 32-38 show additional views of the outboard drive system 400. As can be seen in FIGS. 32-33, the rudder body 1 10 may include an air inlet 301 and an air outlet 302. The air inlet 301 and air outlet 302 may be coupled to an air pump housed within the rudder body 1 10. One or more batteries may be housed within the rudder body 1 10 as well.

[0067] The outboard drive systems disclosed herein may be used in connection with an inflatable watercraft as illustrated in FIGS. 39—40. An inflatable watercraft 500 may include an air inlet 501. The outboard drive system 400 can be used to inflate the inflatable watercraft 500. For example, one end of a hose or other tubing may be connected to the air outlet of the outboard drive system 400 while the other end of the hose or other tubing may be connected to the air inlet 501 of the watercraft 500. The electric motor may be powered by one or more batteries housed within the rudder body 1 10. The electric motor may be further coupled to an air pump. The air pump may draw air in through the air inlet and expel air out of the air inlet and into the inflatable watercraft to inflate the craft. The outboard drive system 400 may then be coupled to the transom 510 of the inflatable watercraft 500 and used to propel the watercraft through the water. The dotted line on the rudder body 1 10 may be indicative of the water line. As shown, the nozzle 175 is positioned above the water line.

[0068] Turning now to the power and control electronics and devices, a wide variety of power sources, motor controllers (see, e.g., 109 of Fig. 1), and motors may be utilized with the drive system disclosed herein. They can be secured in their respective recesses on metal frames and/or plates (not shown) that are secured in the recesses with adhesive and/or with fasteners such as screws to structures in the recesses integral to the side walls or adhesively secured thereto. Acceptable sources of power include a lithium battery or plurality of lithium batteries.

[0069] To avoid a hard wired connection to the motor controllers from a throttle control input, the motor controller advantageously includes a wireless receiver. This receiver can communicate with a wireless transmitter that is controlled by a captain in order to control the motor speed. In one embodiment, wireless transmission circuitry can be configured to transmit electromagnetic and/or magnetic signals underwater. In some embodiments, an automatic shut off may be implemented, where if the signal strength between the transmitter and receiver drops below a certain threshold, indicating a certain distance between the two has been exceeded, the receiver shuts off the electric motor. This is useful as an automatic shut off if a sailor falls overboard. In other embodiments, controls may be located on the tiller. [0070] In some embodiments, a charging port and/or activation switch is disposed on the rudder body and or tiller. Thus, the system may be charged when the system is coupled to a watercraft body or when it is separate from the watercraft body. In some embodiments, one or more exterior surface of the rudder body includes one or more solar panels configured to charge batteries contained therein. In this way, the rudder body may be stored in an area exposed to the sun and the batteries will remain charged. Thus, the system may be ready to be used in an emergency.

[0071] The system can also include one or more grates disposed over intake port or ports of the flow path. The grates can limit access to the impeller and drive shaft to protect these components and/or to prevent a user from inadvertently contacting these components during use. In some embodiments, each grate can be coupled to one or more magnetic switches (not shown) that can deactivate the motor when the grate is separated from the rudder body. Therefore, the one or more magnetic switches may prevent the motor from operating without the optional grate in place.

[0072] The system can include various features to seal and/or protect one or more of its components from an external environment, such as liquid or moisture. In some embodiments, one or more leak detection sensors can be employed to detect moisture or liquid proximate to one or more components of the drive system. Such leak sensors can provide a signal to or within the control system of the system, to providing a leak warning and/or to power-off one or more electrical components within the system. For example, one or more leak detection sensors may be employed proximate to the batteries, to turn off power if liquid is detected, so there are no hot leads proximate to the waterproof battery cases.

[0073] The system may be mounted via the mounting assembly to the port or starboard sidewall of a watercraft body. In some embodiments, the mounting system can be mounted to a transom along the bow or stern of the watercraft body to provide front-side or rear-side propulsion, respectively. Thus, the system can be utilized to provide motorized propulsion capability to an otherwise non-powered watercraft or can be utilized to provide motorized propulsion capability to an otherwise powered watercraft.

[0074] In some embodiments, the system can include a controller configured to regulate power distribution from the batteries. For example, the controller may prevent propulsion by the impellers and motor after a power level of the batteries is less than a threshold value such that a remaining capacity of the batteries can be utilized for deflation of the watercraft. In such instances, the watercraft can be manually propelled or propelled by a separate motor, e.g., an outboard motor or motorized cassette that is coupled to the watercraft. Similarly, the controller can receive an input from one or more pressure sensors configured to sense a pressure of the one or more inflatable chambers. In such embodiments, the controller may regulate power distribution such that the inflatable chambers are inflated if the pressure of the inflatable chambers is less than a threshold value. In some embodiments, the controller can control the aforementioned pump, valve(s) and/or impeller, to control the propulsion, inflation, and/or deflation of the watercraft.

[0075] The above-described embodiments have been provided by way of example, and the present invention is not limited to these examples. Multiple variations and modifications to the disclosed embodiments will occur, to the extent not mutually exclusive, to those skilled in the art upon consideration of the foregoing description. Additionally, other combinations, omissions, substitutions, and modifications will be apparent to the skilled artisan in view of the disclosure herein. Accordingly, the present invention is not intended to be limited by the disclosed embodiments.

[0076] Of course, it is to be understood that not necessarily all objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0077] Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments. For example, the features of the electric drive systems disclosed in the various embodiments can be switched between embodiments. In addition to the variations described herein, other known equivalents for each feature can be mixed and matched by one of ordinary skill in this art to construct drive systems in accordance with principles of the present invention.

[0078] Although this invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above.

[0079] The scope of protection is limited solely by the claims that follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of the specification and prosecution history and to encompass all structural and functional equivalents.