Patent Publication Number: US-8994562-B1

Title: Boat monitoring systems and methods

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 61/567,277, entitled “Boat Monitoring Systems and Methods” and filed on Dec. 6, 2011, which is incorporated herein by Reference. 
    
    
     RELATED ART 
     In a typical boat monitoring system, a boat is equipped with various sensors for monitoring certain conditions indicative of the status of the boat. Information from one or more sensors is automatically reported to a land-based controller usually through a cellular channel. Thus, when a predefined event of interest occurs, the controller can learn of the event and take appropriate action. As an example, a sensor may sense a condition indicating that a fire is occurring on the boat, and the controller may provide a warning so that personnel on land are aware of the fire. 
     Such conventional boat monitoring systems are typically expensive to maintain and operate. In addition, conventional boat monitoring systems also suffer from reliability issues. For example, cellular coverage is limited, particularly for boats, which typically rely on cellular towers on land for communication. Techniques for increasing the robustness and decreasing the costs of boat monitoring systems are generally desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Furthermore, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a block diagram illustrating an exemplary embodiment of a boat monitoring system. 
         FIG. 2  is a block diagram illustrating an exemplary embodiment of a system controller, such as is depicted by  FIG. 1 . 
         FIG. 3  is a block diagram illustrating an exemplary embodiment of a boat monitoring element, such as is depicted by  FIG. 1 . 
         FIG. 4  is a block diagram illustrating a boat monitoring element, such as is depicted by  FIG. 3 , coupled to a plurality of sensors for monitoring conditions on a boat. 
         FIG. 5  is a block diagram illustrating an exemplary embodiment of a boat monitoring system. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure generally pertains to systems and methods for monitoring boats. In one exemplary embodiment, each of a plurality of boats has a respective boat monitoring element that is coupled to various sensors on the same boat. Further, a system controller is configured to communicate with each of the boat monitoring elements via a wireless mesh network. Data indicative of events sensed by the sensors are transmitted to the system controller via such wireless mesh network. The system controller tracks the sensed events and is configured to perform various predefined actions when certain events occur. A remote user may contact the system controller through a wide area network or otherwise to discover the status of a particular boat or to control conditions on the boat. 
       FIG. 1  depicts an exemplary embodiment of a system  10  for monitoring boats  12 . The system  10  may be implemented at a marina or mooring field where boats  12  are typically docked for long periods of time, but the system  10  may be implemented at other locations in other embodiments. The exemplary embodiment shown by  FIG. 1  has a plurality of boats  12  floating in water, such as a lake, river, bay, or ocean, and some of the boats are docked at a pier  15  that extends into the water. 
     Each boat  12  has a boat monitoring element (BME)  22  mounted on the boat  12 , such as within the boat&#39;s engine compartment, but other locations in or on the boat  12  are possible in other embodiments. As will be described in more detail hereafter, each monitoring element  22  is configured to monitor certain parameters indicative of the boat&#39;s safety, security, and/or other type of status and to wirelessly transmit data indicative of such parameters to a system controller  25 . 
     In one exemplary embodiment, the system controller  25  is in close proximity to the boats  12 , such as at a marina where the boats are docked. However, other locations of the system controller  25  are possible. Depending on the distance of the system controller  25  from the boats  12  and the signal strength of the wireless signals transmitted from the boats  12 , there may be one or more repeaters  28  that may be used to extend the effective communication range of the boat monitoring elements  22 . Each such repeater  28  is configured to receive and re-transmit messages from the boat monitoring elements  22  so that the effective communication range of such elements  22  can be extended to reach the system controller  25  if the system controller  25  is out of direct communication range of at least some of the monitoring elements  22 . 
     In addition, in one exemplary embodiment, the boat monitoring controller  25  and the boat monitoring elements  22  on the boats  12  form a wireless mesh network in which each boat monitoring element  22 , as well as the system controller  25  and the repeater  28 , implements a respective node of the wireless mesh network. In such case, a message from any boat monitoring element  22  can hop through other boat monitoring elements  22  or repeaters  28  to reach the system controller  25 . However, other types of networks may be implemented in other embodiments. 
     In addition, the system controller  25  may be configured to transmit messages to the boat monitoring elements  22 . As an example, the controller  25  may transmit control messages causing the boat monitoring elements  22  to perform desired functions or update the boat monitoring elements  22 . Also, the controller  25  may request certain information, such as parameters measured by the boat monitoring elements  22 . Messages transmitted from the controller  25  may hop through any number of nodes (e.g., boat monitoring elements  22  or repeaters) of the wireless network. 
     Each boat monitoring element  22  is assigned an identifier that uniquely identifies it from the other boat monitoring elements  22  of the system  10 . Based on its monitored parameters, the element  22  detects certain events of interest and reports such events to the system controller  25 . As an example, for each detected event, the boat monitoring element  22  may transmit a message for notifying the controller  25  of the occurrence of the event. Such message preferably includes the identifier of the boat monitoring element  22  as well as data indicating the type of event that occurred. The message may also include other information about the event, such as the time and date of the event, as well as the measured parameter on which detection of the event is based. The controller  25  is configured to record information pertaining to the event from the message in data  33 , referred to hereafter as “event data.” 
     As an example, the event data  33  may be stored in a database in which a new entry is created for each detected event. Such entry may have a field for storing the identifier of the boat monitoring element  22  that detected the event, as well as one or more fields for indicating the type of event and/or information about the event (e.g., the time of the event and/or the measured parameter on which detection of the event is based). Thus, the event data  33  can be analyzed at any time to determine which events of interest related to the boats  22  have occurred. Further, for each event, the data  33  indicates on which boat  12  the event occurred. In this regard, as described above, the data  33  indicates the identifier of the boat monitoring element  22  that notified the controller  25  of the event, and such identifier can be used to identify the boat  12  on which the event occurred. That is, the identifier included in the notification message identifies, not only the monitoring element  22  that transmitted the message, but also the boat  12  on which such element  22  resides. 
     In addition to recording events in the event data  33 , the controller  25  is configured to analyze the event data  33  for certain predefined alarm conditions. In this regard, it may be desirable for the controller  25  to generate an alarm when a certain type of event occurs or when a certain parameter monitored by any of the boat monitoring elements  22  is within a certain range (e.g., exceeds a threshold). As an example, one of the parameters may indicate that a fire is occurring on a boat  12  when such parameter exceeds the threshold. In such case, the controller  25  may be configured to generate an alarm to warn one or more users of the detected condition when the parameter exceeds the threshold. In other examples, alarms for other conditions may be rendered. 
     Note that there are various types of alarms that can be generated by the controller  25 . As an example, the controller  25  may generate an audio alarm, such as a buzzer, siren, or prerecorded verbal message, and/or a visual alarm, such as activation of a light or strobe or display of a visual (e.g., textual) message. Such alarms may be rendered at the location of the system controller  25  (e.g., at the marina at which the boats  12  are docked or otherwise in close proximity). In addition, the controller  25  may be configured to cause an alarm to be rendered at a remote location. As an example, the system controller  25  may transmit data indicative of an alarm condition to a communication apparatus  52 , such as a computer (e.g., laptop, desktop, or hand-held computer), a telephone, a pager, a personal digital assistant (PDA), or other type of device, at a remote location. 
     In one exemplary embodiment, the system controller  25  is configured to communicate with the apparatus  52  via a network  55 , such as a telephone or data network. As an example, the network  55  may comprise the Internet, and the controller  25  may be in communication with a gateway  58  that provides access to the network  55 . Upon receiving a message indicative of an alarm condition, the communication apparatus  52  generates an alarm (e.g., an audio or visual message or warning) to warn the user of the apparatus  52  about the alarm condition. Various other techniques for conveying alarms to users are possible in other embodiments. 
       FIG. 2  depicts an exemplary embodiment of the system controller  25 . The controller  25  may be implemented via a computer, such as a laptop, desktop, or hand-held computer, though other types of devices may be used to implement the system controller  25  in other embodiments. As shown by  FIG. 2 , the controller  25  comprises control logic  63  for generally controlling the operation and functionality of the controller  25 , as will be described in more detail below. The logic  63  can be implemented in software, hardware, firmware, or any combination thereof. In the exemplary embodiment illustrated in  FIG. 2 , the control logic  63  is implemented in software and stored in memory  66  of the system controller  25 . 
     Note that the control logic  63 , when implemented in software, can be stored and transported on any computer-readable medium for use by or in connection with an instruction execution apparatus that can fetch and execute instructions. In the context of this document, a “computer-readable medium” can be any means that can contain or store a program for use by or in connection with an instruction execution apparatus. 
     The exemplary embodiment of the system controller  25  depicted by  FIG. 2  comprises at least one conventional processing element  69 , such as a digital signal processor (DSP) or a central processing unit (CPU), that communicates to and drives the other elements within the controller  25  via a local interface  71 , which can include at least one bus. Furthermore, an input interface  73 , for example, a keyboard, keypad, or a mouse, can be used to input data from a user of the controller  25 , and an output interface  75 , for example, a printer or a display device, e.g., a liquid crystal display (LCD), can be used to output data to the user. In addition, a data interface  76  can be used to interface data with the controller  25 . As an example, the data interface  76  may be coupled to the gateway  58  ( FIG. 1 ) for enabling communication between the gateway  58  and the controller  25 . 
     As shown by  FIG. 2 , the system controller  25  also comprises a communication module  77  that is configured to communicate wireless signals (e.g., radio frequency (RF) signals). Such module  77  may be used for communication between the controller  25  and the boat monitoring elements  22 . 
       FIG. 3  depicts an exemplary embodiment of a boat monitoring element  22 . As shown by  FIG. 3 , the element  22  comprises boat monitoring logic  81  for generally controlling the operation and functionality of the element  22 , as will be described in more detail below. The logic  81  can be implemented in software, hardware, firmware, or any combination thereof. In the exemplary embodiment illustrated in  FIG. 3 , the boat monitoring logic  81  is implemented in software and stored in memory  83  of the boat monitoring element  22 . Note that the boat monitoring logic  81 , when implemented in software, can be stored and transported on any computer-readable medium for use by or in connection with an instruction execution apparatus that can fetch and execute instructions. 
     The exemplary embodiment of the boat monitoring element  22  depicted by  FIG. 3  comprises at least one conventional processing element  85 , such as a digital signal processor (DSP) or a central processing unit (CPU), that communicates to and drives the other elements within the element  22  via a local interface  87 , which can include at least one bus. Furthermore, a data interface  88  can be used to interface data with the element  22 . The boat monitoring element  22  also stores in memory  83  predefined threshold data  90  that defines a plurality of thresholds used to detect certain events, as will be described in more detail below. 
     As shown by  FIG. 3 , the boat monitoring element  22  also comprises a communication module  89  that is configured to communicate wireless signals (e.g., radio frequency (RF) signals). Such module  89  may be used for communication between the element  22  and the boat monitoring controller  25 . 
     In one exemplary embodiment, the boat monitoring element  22  has a housing (not shown) for housing components of the element  22 , such as the memory  83 , processing element  85 , and communication module  89 . Further, the data interface  88  may be housed by or coupled to (e.g., mounted on) the housing. In one embodiment, the housing is environmentally hardened to help protect the components of the boat monitoring element  22  from environmental conditions. In particular, the housing is preferably sealed such that it prevents water from entering the housing and contacting the housed components. However, the data interface  88  may be exposed so that it can be connected to external components, as will be described in more detail below. 
     As shown by  FIG. 4 , the boat monitoring element  22  (e.g., the data interface  88  of  FIG. 3 ) is coupled to a plurality of devices  100 - 111  from which the element  22  receives data (e.g., sensor data) about the boat  12  on which the element  22  resides. Based on such data, the element  22  monitors certain parameters and detects events of interest based on such parameters. The boat monitoring element  22  further reports the detected events to the system controller  25  ( FIG. 1 ). In one exemplary embodiment, the boat monitoring element  22  is positioned in the engine compartment of a boat  12 , but other locations of the element  22  are possible in other embodiments. Further, the boat monitoring element  22  is coupled to the devices  100 - 111  via conductive connections, but other types of connections (e.g., optical and/or wireless) may be used, if desired. 
     Referring to  FIG. 4 , the boat monitoring element  22  is coupled to a bilge pump sensor  101 , which is coupled to a bilge pump (not shown) of the boat  12  on which the element  22  resides. As known in the art, a boat&#39;s bilge pump is configured to pump out of the boat  12  water that is within the boat&#39;s hull. A bilge pump may be configured to sense the presence of water within the hull and to then automatically activate in response to such detection. Moreover, high usage (e.g., a high rate of activation and/or long activation durations) of the bilge pump can indicate a problem, such as a leaking hull. 
     The bilge pump sensor  101  is configured to detect when the bilge pump is operating, and the boat monitoring logic  81  is configured to report to the system controller  25  events pertaining to the operation of the bilge pump based on the sensor  101 . As an example, the logic  81  may report the operation times to the controller  25 . As an example, for each activation cycle of the bilge pump, the logic  81  may report such cycle and indicate the duration of the cycle. If the controller  25  determines that the bilge pump usage is abnormal (e.g., operating at an abnormally high frequency and/or for abnormally long periods of time), the controller  25  may generate an alarm for warning a user of the abnormal use of the bilge pump. 
     As an example, in one exemplary embodiment, the logic  81 , based on the messages from the boat monitoring element  22 , calculates a value indicative of an amount of usage of the bilge pump over time (e.g., over many activation cycles of the bilge pump), such as during a certain time period (e.g., the last three months). Further, the logic  81  compares the value to a predefined threshold. If the value exceeds the threshold, then the logic  81  determines that the bilge pump usage is abnormal and generates an alarm. However, if the value is less than threshold, then the logic  63  does not generate an alarm. 
     Note that there are various techniques that can be used to determine when the bilge pump is operating. In one exemplar embodiment, the bilge pump is powered by a battery. When activated, the bilge pump draws current from the battery. The bilge pump sensor  101  is configured to detect when the bilge pump is drawing at least a threshold amount of current. As an example, the sensor  101  may be configured to detect the current or voltage of a wire connecting the bilge pump to the battery and determine that the bilge pump is operating when the detected parameter exceeds a predefined threshold. Yet other techniques for sensing the operation of the bilge pump are possible in other embodiments. 
     The boat monitoring element  22  is also coupled to a battery sensor  102 , which is used to monitor a voltage of the boat&#39;s battery (not shown). If the sensed voltage falls below a predefined threshold, as indicated by the threshold data  90 , then the boat monitoring logic  81  reports such event to the system controller  25 . The occurrence of this event may indicate that the battery has been sufficiently discharged such that imminent replacement of the battery is needed or desired. The controller  25  may be configured to trigger an alarm in response to the occurrence of such an event. 
     As shown by  FIG. 4 , the boat monitoring element  22  is further coupled to a shock sensor  103 , which is configured to sense when the boat  12  experiences a significant shock such as when the boat  12  collides with an object (e.g., another boat  12  or land). In one exemplary embodiment, the shock sensor  103  is implemented via an accelerometer that detects acceleration. If the sensed acceleration exceeds a threshold, as indicated by the threshold data  90 , then the boat monitoring logic  81  reports such event to the system controller  25 . The occurrence of this event may indicate that the boat  12  has just been involved in an accident. The controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     The boat monitoring element  22  is coupled to an inclination sensor  104 , which is configured to sense an inclination angle or tilt of the boat  12 . In one exemplary embodiment, the inclination sensor  104  is implemented via an accelerometer that is calibrated to a level reference point. The inclination sensor  104  alternatively could be implemented by a conventional mercury switch that is configured to measure tilt. Other types of known sensors for measuring tilt may be used. If the sensed inclination angle exceeds a threshold, as indicated by the threshold data  90 , then the boat monitoring logic  81  reports such event to the system controller  25 . The occurrence of this event may indicate that the boat  12  is listing. The controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     The boat monitoring element  22  is also coupled to an alternating current (AC) voltage sensor  105 , which is configured to sense the AC voltage of the water near the boat  12 . In this regard, due to an electrical fault or otherwise, it is possible for the boat&#39;s electrical system or other electrical source in the vicinity of the boat  12  to apply a voltage to the water at a high enough level to be dangerous to people who come into contact with the water. In one exemplary embodiment, the AC voltage sensor  105  has a pair of electrodes (not shown) that are positioned in the water, and the sensor  105  measures the AC voltage across the electrodes. If the sensed voltage exceeds a threshold, as indicated by the threshold data  90 , then the boat monitoring logic  81  reports such event to the system controller  25 , and the controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     The boat monitoring element  22  is further coupled to a fire sensor  106 , which is configured to sense when the boat  12  on fire. In one exemplary embodiment, the fire sensor  106  is implemented via a smoke detector or an oxygen detector. If the sensed level of smoke exceeds a threshold, as indicated by the threshold data  90 , or if the sensed level of oxygen falls below a threshold, as indicated by the threshold data  90 , then the boat monitoring logic  81  reports such event to the system controller  25 . The controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     Note that a temperature sensor  100  also may be used to indicate a fire condition on board the boat. If the sensed temperature exceeds a threshold, as indicated by the threshold data  90 , then the boat monitoring logic  81  reports such event to the system controller  25 , and the controller  25  may be configured to trigger an alarm in response to the occurrence of such event. In some embodiments, the boat monitoring logic  81  is configured to monitor a plurality of sensors to determine when a fire event is occurring and to then report the event based on such determination. As an example, if the level of smoke is within a certain range, as indicated by the threshold data  90 , then the boat monitoring logic  81  may be configured to report the occurrence of a fire only if the temperature sensed by the sensor  100  exceeds a certain threshold, as indicated by the threshold data  90 . The controller  25  may be configured to trigger an alarm in response to the occurrence of such event. However, if the level of smoke is greater than the range indicated in the foregoing example, then the controller  25  may be configured to trigger an alarm regardless of the state of the temperature sensor  100  alternatively the threshold used for the temperature sensor  100  may be lowered. 
     In addition to reporting hot temperatures, the boat monitoring logic  81  may also be configured to report when the temperature measured by the sensor  100  falls below a threshold, as indicated by the threshold data  90 . The controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     In some situations, it may be desirable to know when a person is on board the boat  12 . In this regard, a boat  12  may be left at the marina or other location unattended, and it may be desirable to know if an unauthorized person has boarded the boat  12 . In one exemplary embodiment, the boat monitoring element  22  is coupled to a user interface  107  that allows a user to exchange data with the boat monitoring element  22 . As an example, the user interface  107  may have a keypad for allowing a user to provide inputs. The user interface  107  may also have a display (e.g., a liquid crystal display (LCD)) and/or speaker for allowing outputs to be displayed or otherwise rendered to the user. Any of the events detected by the boat monitoring element  22  may be reported to the user interface  107  in addition to or in lieu of the controller  25  so that a user on board the boat  12  can be informed of such detected events. 
     In one embodiment, an authorized user uses the interface  107  to indicate when certain sensors should be monitored, and such sensors indicate the presence of a person on board the boat  12 . As an example, such sensors may include a light sensor  108 , a door sensor  109 , and/or a motion sensor  110 . When the user desires the sensors to be monitored, the user provides an input that causes the boat monitoring logic  81  to begin monitoring the sensors  108 - 110 . When the user no longer desires the logic  81  to monitor the sensors  108 - 110 , the user provides another input that causes the logic  81  to stop monitoring the sensors  108 - 110 . As an example, the user may activate monitoring of the sensors  108 - 110  upon leaving the boat  12  and then deactivate the sensors  108 - 110  upon returning to the boat  12 . Thus, if any of the sensors  108 - 110  detect the presence of a person while monitoring of such sensor is activated, then it is likely that such person is an intruder who is not authorized to be on the boat  12 . The boat monitoring logic  81  is configured to report such event to the controller  25 , and the controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     The light sensor  108  is configured to sense light. The sensor  108  may be positioned in the boat&#39;s engine compartment or inside stateroom. If a door is opened to the room in which the sensor  108  is located, light may enter the room through the door causing the amount of light measured by the sensor  108  to increase. If the sensed light exceeds a threshold, as indicated by the threshold data  90 , while the sensor  108  is being monitored, then the boat monitoring logic  81  reports such event to the system controller  25 , and the controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     The door sensor  108  is configured to sense when a door of the boat is opened. Such a sensor  108  may be implemented by a contact switch or some other switch commonly used to sense when doors or windows are opened. If the sensor  108  senses opening of a door while it is being monitored, then the boat monitoring logic  81  reports such event to the system controller  25 , and the controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     The motion sensor  110  is configured to sense motion. There are various types of sensors known for performing this function. In one exemplary embodiment, the motion sensor  110  is implemented via an infrared sensor, but other types of sensors may be used in other embodiments. If the sensor  110  detects motion while it is being monitored, then the boat monitoring logic  81  reports such event to the system controller  25 , and the controller  25  may be configured to trigger an alarm in response to the occurrence of such event. 
     In one exemplary embodiment, the boat monitoring element  22  is coupled to a camera  111  that is mounted on the boat  12  and configured to capture images. The camera  111  may capture still frames and/or video images. The images captured by the camera  111  may be stored by the boat monitoring element  22  for later retrieval, if desired. In one exemplary embodiment, the images are stored to a circular buffer in which the images are overwritten by new images over time. The images may be written to the buffer continuously or at certain times. As an example, the images captured by the camera  111  may be written to the buffer periodically or in response to a detection by any of the sensors  108 - 110  for sensing the presence of an unauthorized person. 
     If desired, the images captured by the camera  111  may be transmitted by the boat monitoring logic  81  to the controller  25 . The images may be continuously transmitted, such as for example to provide a live feed. Alternatively, the images may be transmitted periodically or in response to a detection by any of the sensors  108 - 110  for sensing the presence of an unauthorized person. The controller  25  may be configured to display and/or store the received images. 
     In one exemplary embodiment, the boat monitoring element  22  is coupled to a plurality of devices  152 - 154  for which the element  22  provides control input. As an example, the boat monitoring element  22  may be coupled to a temperature control device  152  that is configured to control air temperature within a compartment or room of the boat  12 . As an example, the temperature control device  152  may comprise a thermostat that is configured to control a heating or cooling system (not shown) on board the boat  12  for heating or cooling air in one or more rooms or compartments of the boat  12 . The boat monitoring logic  81  may directly control the activation state of the heating or cooling system or control the activation state indirectly by controlling the set point of the thermostat or otherwise. 
     As known in the art, a “set point” generally refers to a temperature threshold that is used to control the activation state of a heating or cooling system. For example, if the temperature sensed by a thermostat falls below a set point for a heating system, the thermostat is configured to activate the heating system thereby causing it to emit heat. Once the sensed temperature rises above the set point, the thermostat is configured to deactivate the heating system. Thus, the heating system maintains room temperature within a range close to the set point. Similarly, the thermostat controls a cooling system to maintain room temperature close to a set point by activating the cooling system when the sensed temperature rises above the set point and by deactivating the cooling system when the sensed temperature falls below the set point. Note that multiple set points (e.g., upper and lower set points) may be used to provide a desired amount of hysteresis. 
     In one exemplary embodiment, the boat monitoring logic  81  controls the temperature control device  152  based on information from the system controller  25 . As an example, the system controller  25  may store control data  142  ( FIG. 2 ) that is generally defined to indicate how various devices on board each boat  12  is to be controlled. The control data  142  may be defined individually for each boat  12  so that one boat  12  can be controlled differently from another. The portion of the control data  142  pertaining to a particular boat  12  is preferably correlated in the data  142  with the boat&#39;s identifier so that the identifier may be used as a key to search and find such portion. 
     For illustrative purposes, assume that for one of the boats  12  the control data  142  ( FIG. 2 ) defines a temperature schedule indicating that the set point used by the temperature control device  152  is to change over time. In this regard, the set point may be set to one temperature at night and a different temperature during the day. Alternatively, the set point or points used during winter may be different than those used during summer. In any event, based on the control data  142 , the control logic  63  of the system controller  25  determines the appropriate set point for the present time period. If the set point is to change relative to the current set point being used by the temperature control device  152 , the control logic  63  of the system controller  25  is configured to transmit a message to the boat monitoring element  22 , which then communicates with the temperature control device  152  to appropriately change the set point. 
     In another exemplary embodiment, the system controller  25  determines a temperature on board the boat via the temperature sensor  100 , as described above or otherwise. The control logic  63  of the system controller  25  then compares the sensed temperature to a current set point indicated by the control data  142  and, based on such comparison, determines whether the activation state of the boat&#39;s heating or cooling system is to change. If it is to change, the control logic  63  of the system controller  25  transmits a message to the boat monitoring element  22 , which then communicates with the temperature control device  152  is order to cause the device  152  to activate or deactivate the heating or cooling system as appropriate. In such an embodiment, the temperature control device  152  may be configured to transmit an enable signal to the heating or cooling system. If the enable signal is asserted, the heating or cooling system is activated. However, if the enable signal is deasserted, the heating or cooling system is deactivated. 
     In yet other embodiments, a user may provide inputs via the communication apparatus  52  or otherwise for controlling the heating or cooling system. As an example, the user may provide an input for setting the set point used to control the operation of the heating or cooling system. Alternatively, the user input may request that the activation state of the heating or cooling system be changed. In response to the user input, the system controller  25  is configured to communicate with the boat monitoring element  22 , as described above, so that the heating or cooling system is controlled in the desired manner via the temperature control device  152 . Yet other techniques may be used to control the operation of the temperature control device  152  in other embodiments. 
     As shown by  FIG. 4 , in one exemplary embodiment, the boat monitoring element  22  is coupled to and controls the state of a valve  153  that is used to control water flow through water pipes  163 , which pass water from a water source  166  (e.g., a tank or a body of water in which the boat  12  is floating) to a water dispensing apparatus  167 , such as a faucet. In this regard, during periods of cold weather, it is possible for water within the pipes  163  to freeze into ice causing the pipes to later burst when the ice begins to thaw. In such case, water may undesirably continue leaking from the pipes  163  into the boat  12 . 
     The valve  153  is configured to selectively block the flow of water through the pipes  163  based on a control signal received from the boat monitoring element  22 . In this regard, the boat monitoring element  22  transmits a control signal for selectively transitioning the valve  153  between an open state and a closed state. When in the open state, the valve  153  permits water to flow so that water from the water source  163  may flow through the pipes  163  and valve  153  to the water dispensing apparatus  167 . When in the closed state, the valve  153  blocks water from flowing so that water is prevented from flowing past the valve  153  to the water dispensing apparatus  167 . When the valve  153  is in the closed state, bursting of the pipes  163  due to cold weather may be prevented and/or, if there is a leak in the pipes  163  between the valve  153  and the water dispensing apparatus  167 , water may be prevented from leaking from the pipes  163  into the boat  12 . 
     In one exemplary embodiment, the boat monitoring logic  81  controls the valve  153  based on information from the system controller  25 . In this regard, the control data  142  is defined to indicate when the valve  153  is to be transitioned from one state to another. As an example, the control data  142  may indicate that the valve  153  is to be transitioned to the closed state when the temperature sensed by the temperature sensor  100  falls below a predefined threshold. In such embodiment, when the system controller  25  receives a message from the boat monitoring element  22  indicating that the temperature sensor  100  has sensed a temperature below the threshold, the control logic  63  of the controller  25  is configured to transmit a message to the boat monitoring element  22  indicating that the valve  153  is to be transitioned to the closed state. In response, the boat monitoring logic  81  transmits a control signal to the valve  153  for transitioning it to the closed state. Thus, when the sensed temperature falls below the threshold, the valve  153  is automatically transitioned to the closed state. 
     In another example, the state of the valve  153  is controlled based on time. In this regard, the control data  142  may define a schedule for controlling the state of the valve  153 . For example, the boat  12  may be “winterized” by transitioning the valve  153  to the closed state at the beginning of winter, and the valve  153  may be later transitioned to the open state at the end of winter. In such case, the control data  142  indicates the dates that the valve  153  is to be respectively opened and closed, and the system controller  25 , based on such data  142 , is configured to communicate with the boat monitoring element  22  such that the state of the valve  153  is automatically transitioned at the appropriate times. 
     In yet other embodiments, a user may provide inputs via the communication apparatus  52  or otherwise for controlling the state of the valve  153 . As an example, the user may provide an input for either opening or closing the valve  153 . In response to the user input, the control logic  63  of the system controller  25  is configured to communicate with the boat monitoring element  22 , as described above, so that the boat monitoring logic  81  transitions the valve  153  to the desired state. Yet other techniques may be used to control the state of the valve  153  in other embodiments. 
     As shown by  FIG. 4 , the boat monitoring element  22  is also coupled to and controls a battery charger  154  that is coupled to and used to charge the boat&#39;s battery (not shown). In this regard, the boat monitoring element  22  transmits a control signal for selectively transitioning the battery charger  154  between a charging state and an idle state. When in the charging state, the battery charger  154  charges the battery. When in the idle state, the battery charger  154  refrains from charging the battery. 
     In one exemplary embodiment, the boat monitoring element  22  controls the battery charger  154  based on information from the system controller  25 . In this regard, the control data  142  is defined to indicate that the boat&#39;s battery is to be charged when the battery sensor  102  senses a voltage or other parameter below a predefined threshold. In such embodiment, when the system controller  25  receives a message from the boat monitoring element  22  indicating that the battery sensor  102  has sensed a voltage below the threshold, the control logic  63  of the controller  25  is configured to transmit a message to the boat monitoring element  22  indicating that the battery charger  154  is to be transitioned to the charging state. In response, the boat monitoring logic  81  transmits a control signal to the battery charger  154  for transitioning it to the charging state. Thus, when the sensed voltage falls below the threshold, the battery charger  154  is controlled such that it automatically begins charging the battery. Once an upper voltage threshold is reached due to the charging, a similar process may be used in order to control the battery charger  154  such that it stops charging the battery. 
     In yet other embodiments, a user may provide inputs via the communication apparatus  52  or otherwise for controlling the state of the battery charger  154 . As an example, the user may provide an input for causing the battery charger  154  to either begin charging the battery or to stop charging the battery. In response to the user input, the control logic  63  of the system controller  25  is configured to communicate with the boat monitoring element  22 , as described above, so that the boat monitoring logic  81  transitions the battery charger  154  to the desired state. Yet other techniques may be used to control the state of the battery charger  154  in other embodiments. 
     In one exemplary embodiment, each boat  12  is registered with the system controller  25  in a registration process that precedes monitoring of such boat  12  by the controller  25 . During registration, the identifier of the boat&#39;s monitoring element  22  (which also identifies the boat  12  and is used in the communication between such BME  22  and the controller  25 ) is stored in registration data  121  ( FIG. 2 ) maintained by the controller  25 . The entry in the registration data  121  also includes other data pertaining to the monitoring of the identified boat. As an example, the data  121  may include the name and contact information of a person (e.g., the boat owner) associated with the identified boat  12 . The entry also may include information about a financial account (e.g., credit card account) that can be used to charge fees. As an example, the services provided by the controller  25  may be charged to such financial account periodically. The entry also may include information (e.g., telephone number, pager number, email address, etc.) for enabling the controller  25  to send an alarm message to the communication apparatus  52 . When the controller  25  receives a message indicating an occurrence of an event for which the controller  25  is to report an alarm, the control logic  63  uses the boat identifier included in the message to lookup in the registration data  121  the contact information to be used to send the alarm. The logic  63  then sends the alarm using such contact information. 
     The registration data  121  is also used by the control logic  63  to track when boats  12  that have not registered with the controller  25  have entered or come within close proximity of the marina or other location. Such an occurrence may be a security threat, particularly during certain hours of the day (such as at night or early morning) when significant traffic is not expected, or may indicate that someone is improperly using or exploiting the services of the marina. 
     Note that there are a variety of techniques that can be used to determine whether a boat  12  is within a particular region of interest, such as within close proximity of a marina. As an example, the boat monitoring element  22  may be coupled to a location sensor, such as a global positioning system (GPS) sensor, and the boat monitoring logic  81  may determine and report to the controller  25  the location of the boat  12  based on such location sensor. In another embodiment, a node of the network (such as the repeater  28 ) at a fixed location communicates with the boat monitoring element  22  and measures the signal strength of a signal received from such element  22  to estimate the distance of the boat  12  from such node. Based on such distance, the control logic  63  can determine whether the boat  12  is within the marina or other region of interest. 
     Various other techniques may be used to determine the distance between the boat and a fixed location, such as a repeater  28 . For example, there exist various ranging algorithms where two nodes communicate with each other to determine the distance between the nodes. In some embodiments, the time of flight of messages communicated between the two nodes is measured in order to calculate the distance between the two nodes. Essentially, the distance is greater for longer times of flight. In another embodiment, the distance is estimated based on the phase relationship of signals communicated between the nodes. Any such ranging algorithms may be employed to determine the distance of the boat  12  from a fixed location, such as the repeater  28 . 
     Moreover, if the control logic  63  receives a message from a boat  12  that is within the region of interest but not identified by the registration data  121 , then the logic  63  identifies such boat  12  as “unregistered.” For as long as the unregistered boat  12  remains in the region of interest (e.g., at the marina or within a predefined distance of the repeater  28  or other node), the control logic  63  tracks the boat  12  and stores information about the boat  12 . As an example, the logic  63  may store the boat&#39;s identifier and the times that the boat  12  is detected to be within the region of interest. If the boat  12  continuously stays in such region of interest for longer than a specified duration, then the control logic  63  triggers an alarm to notify a user of such event. In response, the user may look for the identified boat  12  and investigate whether the boat&#39;s personnel are improperly using or exploiting the services of the marina. 
     In another example, if an unregistered boat  12  is within the region of interest during certain time periods, such as at night, the control logic  63  may be configured to trigger an alarm. There are various other actions that the control logic  63  could take in response to a detection of an unregistered boat  12 . 
     Note that the controller  25  can be configured to track registered boats  12  at any location from which a given boat  12  is within range of the controller  25 . Such range can vary as boats  12  move since a given boat  12  can communicate with the controller  25  through the BMEs  22  of other boats  12 . In fact, a boat  12  can be a long distance from the controller  25  such that direct communication with the controller  25  is not possible but nevertheless still communicate with the controller  25  by hopping messages through the BMEs  22  of other boats  12 . However, in one exemplary embodiment, the control logic  63  is configured to only monitor boats  12  that are within a certain region of interest (e.g., at or within a certain distance of the marina). 
     In this regard, the control logic  63  may be configured to determine whether a given registered boat  12  is within a region of interest using any of the techniques described above for determining whether an unregistered boat  12  is within a region of interest. As long as a registered boat  12  remains within such region of interest, the control logic  63  communicates with the boat&#39;s BME  22  and tracks events of interest, as described herein. Further, the control logic  63  may trigger an alarm for any such event. However, once the boat  12  leaves the region of interest, the control logic  63  stops tracking the boat  12 . That is, the control logic  63  stops updating the event data  33  based on communications with the boat&#39;s BME  22 , as well as stops analyzing data from the boat  12  for determining whether to trigger an alarm. However, once the boat  12  re-enters the region of interest or enters another region of interest, the control logic  63  resumes monitoring the boat  12 , as is described herein. Note that selective monitoring of the boat  12  is optional, and in other embodiments, the control logic  63  may be configured to continuously monitor a given boat  12  for as long as it remains in communication with the system controller  25 . 
       FIG. 5  depicts another exemplary embodiment of a boat monitoring system  10 . As can be seen by comparing  FIG. 1  and  FIG. 5 , the system  10  of  FIG. 5  is similar to that of  FIG. 1  except that the boat monitoring controller  25  is located at a remote location and communicates with the boat monitoring elements  22  through the network  55 , such as for example the Internet. In such example, the gateway  58  encapsulates the messages from the boat monitoring elements  22  into IP packets (or other protocol compatible with the network  55 ) for transmission through the network  55 . 
     In one exemplary embodiment, the system controller  25  hosts a website that can be used to access the event data  33 . As an example, a user of the communication apparatus  52  or other device can contact the system controller  25  via the network  55  and access the event data  33 . In one exemplary embodiment, the user is authenticated for a particular boat  12  and is allowed to access only the data  33  pertaining to the boat  12  for which he or she is authenticated. 
     In another exemplary embodiment, a system controller  25  may be implemented remotely, as shown by  FIG. 5 , and also locally, as shown by  FIG. 1 . Thus, personnel at the marina may locally monitor the boats  12  while users (e.g., boat owners, personnel of insurance companies insuring the boats  12 , or others) can monitor the boats  12  remotely. If desired, an system controller  25  may be implemented locally, and upload the event data  33  to a remote server via the network  55  to provide access to the data  33  for remote users. Also, a system controller  25  implemented locally, as shown by  FIG. 1 , could be configured to host a website or otherwise provide remote access to the event data  33  such that implementation of a remote server is unnecessary. 
     It should be noted that, for any given alarm, the decision of when to generate the alarm and/or which detected events should trigger the alarm may be made by control logic  63  or the boat monitoring logic  81 . For example, upon detecting the occurrence of an event that should trigger an alarm, the boat monitoring logic  81  may be configured to transmit a message for instructing the control logic  63  to generate an alarm. Alternatively, the boat monitoring logic  81  may transmit a message indicative of the event, and the control logic  63  may decide whether an alarm is to be generated in response to the event. Various other configurations and changes would be apparent to a person of ordinary skill upon reading this disclosure.