A recreational fishing boat is often equipped with a trolling motor for propelling the boat through a suspected fish habitat while an operator fishes. The navigation route of the fishing boat through the habitat is selected by the operator based upon a number of factors. The factors typically include the water depth, the water temperature including the location of thermoclines (boundaries between bodies of water with contrasting temperatures), the topography of the bottom including natural or man-made structures, the composition of the bottom (e.g., sand; rocks; weeds), the current and the location of shorelines and/or other above-water obstacles. A desired navigation route may also depend on the need to travel from one location to another, such as from a boat launch pad or dock to the general vicinity of a desired fishing area, or by the operator's experience and intuition. Once a particular navigation route is selected, the operator may desire to repeat the route a number of times while fishing.
Originally, an operator was required to operate a trolling motor manually. However, the attention and time required to operate the trolling motor interfered with the fishing activity itself. In response, a number of systems have evolved to automatically control the operation of a trolling motor, thereby allowing the operator to devote her attention and time to fishing. One known system controls a trolling motor to maintain a selected distance between a fishing boat and a shoreline or fixed structure. Another system controls a trolling motor to maintain a selected water depth beneath a boat. Yet another system controls a trolling motor to maintain a boat at a desired heading. Another system controls a trolling motor to maintain a boat in a fixed position.
Known control systems, however, do not provide an operator with flexibility in setting a desired route. As described above, a desired navigation route may depend on a number of factors combined in various ways at the discretion of the operator. For example, the operator may want to set a navigation route as a fishing boat is manually navigated through a suspected fish habitat while the operator monitors any or all of the above factors. Once a navigation route is selected, the operator may want to repeatedly navigate the fishing boat around the navigation route, either in forward or reverse order, while fishing. It would be advantageous to provide a system that allows an operator to select a navigation route by entering waypoint positions, or waypoints, representing successive positions along the navigation route. Such a system would allow an operator to select waypoints using any factor or combination of factors that is desirable, and would control a trolling motor to navigate a fishing boat between the selected waypoints.
Accordingly, it would be desirable to provide a flexible system for controlling the navigation of a fishing boat equipped with a trolling motor. It would also be desirable to provide a system for controlling the navigation of a fishing boat between a plurality of waypoints representing successive positions around a navigation route. Further, it would be desirable to provide a system for controlling the repeated navigation of a fishing boat around a navigation route. It would also be desirable to provide a system for controlling the navigation of a fishing boat around a navigation route represented by a plurality of waypoints stored manually via a keypad or a switch, downloaded from an electronic chart, or stored automatically by the system based on actual position as an operator navigates around the navigation route.