3.24 Interpreting the Display

Zero line

The zero line (sometimes referred to as the transmission line) represents the transducer’s position, and moves off the screen when a deep phased range is used.

Zero line

Shift

Figure 3-21 Zero line

Fish school echoes

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

Bottom echo

Echoes from the bottom are normally the strongest and are displayed in reddish brown color (in default color arrangement) but the color and width will vary with bottom com- position, water depth, frequency, sensitivity, etc.

In a comparatively shallow depth, a high gain setting will cause a second or sometimes a third or a fourth echo to be displayed at the same interval between them below the first echo trace. This is because the echo travels between the bottom and the surface twice or more in shallow depths.

The color of the bottom echo can be used to help determine the density of the bottom ma- terials (soft or hard). The harder the bottom, the wider the trace. If the gain is set to show only a single bottom echo on mud, rocky bot- tom will show a second or third bottom re- turn. The range should be chosen so the first and second bottom echoes are displayed when bottom hardness is being determined.

Intensity difference in water depth

Second bottom echo

Size of fish school

Small Large school school

Rock base

Mud and sand

Figure 3-22 Fish school echoes

Figure 3-23 Bottom echoes

3-10

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Furuno GP-1610CF manual Interpreting the Display, Zero line, Fish school echoes, Bottom echo

GP-1610CF specifications

The Furuno GP-1610CF is a sophisticated marine navigation system designed for enthusiasts who demand accuracy and reliability on the water. Featuring a 10.4-inch color LCD display with a resolution of 640 x 480 pixels, this unit provides crystal-clear images of charts and navigation information, even under direct sunlight. Its user-friendly interface allows for intuitive management of various functions, making it accessible for both novice and experienced mariners.

One of the standout features of the GP-1610CF is its integrated GPS receiver, which boasts a high sensitivity that ensures rapid acquisition of satellite signals and precise positioning. The unit supports a range of positioning formats, including WAAS (Wide Area Augmentation System), allowing for enhanced accuracy within the coastal dimensions. Additionally, the GP-1610CF is compatible with DGPS (Differential GPS) systems, further refining positional accuracy and providing a reliable navigation experience.

The GP-1610CF also supports C-MAP NT+ charting, offering an extensive variety of cartographic data covering numerous regions. This enables users to visualize marine environments with detailed bathymetric information, harbor layouts, and navigational aids. The system's customizable waypoints and route planner facilitate efficient marine navigation, allowing users to create multiple routes and track them in real time.

In terms of connectivity, the GP-1610CF offers NMEA 0183 output, which allows it to interface seamlessly with other marine electronics such as autopilots, radar systems, and depth sounders. This enabling communication between devices enhances overall situational awareness and improves navigation assistance.

The unit is built to withstand the harsh marine environment, featuring a robust housing that is resistant to saltwater, humidity, and temperature variations. Additionally, the GP-1610CF can function in challenging lighting conditions thanks to its adjustable contrast and brightness settings, which help maintain visibility during nighttime operation.

Overall, the Furuno GP-1610CF stands as a reliable choice for sailors seeking a high-performance navigation solution. With its combination of advanced GPS technology, high-resolution display, extensive chart compatibility, and robust design, this device continues to be a trusted companion for marine adventures around the globe. Whether cruising, fishing, or engaging in professional navigation, the GP-1610CF delivers essential features that empower users to navigate with confidence and accuracy.