User manual NORTHSTAR EXPLORER 443D

[. . . ] Explorer 443d/443df Fishfinder Installation and Operation Manual www. northstarnav. com IMPORTANT SAFETY INFORMATION Please read carefully before installation and use. DANGER !It is used to alert you to potential personal injury hazards, Obey all safety messages that follow this symbol to avoidpossible injury or death. WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury CAUTION indicates a potentially hazardous situation which, if not avoided, could result in minor or moderate injury. CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in property damage. WARNING CAUTION CAUTION DISCLAIMER: It is the owner's sole responsibility to install and use the instrument and transducers in a manner that will not cause accidents, personal injury or property damage. [. . . ] This might indicate a thermocline - a rapid change in water temperature, such as the edge of a warm or cold current. The temperature difference can form a barrier which the fish may not swim through. In fresh water, fish often collect around a thermocline. Fish symbols Off For experienced users this always provides the best information as every echo is displayed, whether it is surface clutter, a thermocline or a fish. The picture in section 4-1 Interpreting the display, shows the Sonar display with the Fish symbols Off. The fish appear as arches. Fish arches In good conditions and with Fish symbols Off, a fish passing through the cone-shaped ultrasonic pulse is displayed as a fish arch. A fish arch occurs when a fish enters the weak edge of the sonar cone, generating a weak echo that is displayed as the first pixel of the fish arch. As the fish moves closer to the middle of the cone, the distance between the transducer and the fish reduces and the echo is displayed at progressively shallower depths, producing the start of an arch. When the fish passes directly beneath the middle of the cone, the echo becomes strongest and thickest. As the fish passes out of the middle of the cone the reverse happens with a progressively weaker and deeper echo. For example: · · Fish symbols The fish symbol can be customized or switched off altogether so that the echoes are not converted to fish symbols on the display. The differences between Fish symbol On and Off are: Fish symbols On Using Northstar's SBN-II sonar technology the fishfinder analyses all echoes and eliminates most false signals and clutter so that remaining targets are most likely fish. Depending on the strength of the remaining echoes, they are displayed as either small, medium or large fish symbols - with or without depth. While the SBN-II processing is very sophisticated it is not foolproof - there will be times when the fishfinder will not be able to differentiate between large air bubbles, rubbish containing air, fishing floats etc. The picture shows the Sonar display with the Fish symbol: symbol + depth: Poor transducer installation (see Transom Transducers Installation Guide). If the boat is anchored then fish will tend to show on the display as horizontal lines as they swim into and out of the transducer sonar beam. It will be much easier to see fish arches when using zoom mode to concentrate on a particular section of water, rather than just displaying everything from the surface to the bottom. Zooming increases screen resolution and is necessary for good fish arches. · Northstar Explorer 443d/443df Installation and Operation Manual 21 · It is difficult to get fish arches in shallow water as the transducer sonar beam is very narrow near the surface and fish do not stay within the beam long enough to display an arch. Several fish in shallow water tend to display as randomly stacked blocks of pixels. Wave motion may result in distorted fish arches · 4-4 Gain Gain (sensitivity) controls the amount of detail displayed on the Explorer 443d/443df. Understanding how to set suitable Gain settings is important for optimum performance. The Northstar fishfinder has three gain modes, Cruising, Fishing and Manual. · Cruising Mode Use this mode to show only the bottom and large fish. [. . . ] Consequently, the Fuel remaining value will be higher than the actual amount of fuel remaining in the tank. To avoid this problem, use the Auto Power Wiring option described in section 6-5 Wiring options. This ensures that the fishfinder powers on automatically whenever the boat's ignition is switched on. b) In rough seas, fuel may surge back and forth through the fuel transducer, resulting in incorrect readings. [. . . ]