4. VIDEO SOUNDER OPERATION

4.14.3Fish school echoes

Fish school echoes will generally be plotted between the zero line and the bottom. Usually the fish school/fish echo is weaker than the bottom echo because its reflection property is much smaller compared to the bottom. The size of the fish school can be ascertained from the density of the display.

Size of fish school

Small Large school school

Fish school echoes

4.14.4Surface noise/Aeration

When the waters are rough or the boat passes over a wake, surface noise may appear near the zero line. As surface turbulence is acoustically equivalent to running into a brick wall, the bottom echo will be displayed intermittently. Similar noise sometimes appears when a water temperature difference (thermocline) exists. Different species of fish tend to prefer different temperature zones, so the thermocline may be useful to help identify target fish. 200 kHz tends to show shallow thermoclines better than 50 kHz.

In rough waters the display is occasionally interrupted due to below-the-ship air bubbles obstructing the sound path. This also occurs when the boat makes a quick turn or reverses movement. Lowering the picture advance speed may reduce the interruption. However, reconsideration of the transducer installation may be necessary if the interruption occurs frequently.

Surface noise

Caused by aerated water

Thermocline

Surface noise/aeration

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Furuno 1933C, 1943C, 1833C manual Fish school echoes, Surface noise/Aeration, Surface noise/aeration

1833C, 1933C, 1943C specifications

Furuno is a well-respected name in marine electronics, renowned for producing high-quality navigation and fish-finding equipment. Among their product line, the Furuno 1943C, 1953C, 1933C, GD-1900C, and 1833C stand out as reliable radar systems, providing exceptional performance and advanced features for both commercial and recreational vessels.

The Furuno 1943C is a powerful 12 kW radar system, boasting a 10.4-inch monochrome display with a user-friendly interface. It is equipped with digital signal processing (DSP) technology that enhances target detection and resolution. The 1943C offers superior target tracking capabilities, even in challenging weather conditions. Its patented Auto Gain Control ensures that small targets are not lost in clutter, making it a favorite among serious navigators.

Moving on to the Furuno 1953C, this model has an impressive 12 kW output and features a high-resolution 15-inch color display. It integrates advanced features such as Automatic Radar Plotting Aid (ARPA) for tracking multiple targets simultaneously, increasing situational awareness and safety on the water. Additionally, the 1953C offers a range of presentation modes, allowing users to customize the display to their specific needs.

The Furuno 1933C is a compact yet efficient radar solution with a 6 kW output and a 10.4-inch monochrome display. This system is highly regarded for its reliable performance and ease of use. Its user-friendly interface makes navigation simple, while features such as Target Analyzer and Echo Trails aid in identifying potential hazards, ensuring safe passage through busy waterways.

The Furuno GD-1900C combines chartplotting and radar in a single unit. With a 10.4-inch color display, it provides clear visuals of radar data as well as navigation charts. The GD-1900C supports various chart formats, including C-MAP and Navionics, allowing boaters to access detailed navigational information. This system is especially useful for those who need both radar and chartplotting capabilities in a space-saving design.

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In summary, Furuno’s range of radar systems, including the 1943C, 1953C, 1933C, GD-1900C, and 1833C, demonstrates the brand’s commitment to quality and innovation in marine technology. Each unit incorporates advanced features tailored to meet the diverse needs of boaters, ensuring safe and efficient navigation on the water.