Chart Plotter and Fish Finder: The Network Is the Real Feature

A chart plotter and fish finder pairing usually starts as one unit and becomes a network

Two Screens That Share One Antenna

A chart plotter and fish finder pairing usually starts as one unit and becomes a network. ONWA's KM-8 and KM-12 run 1024×768 on 8- and 12-inch daylight TFT panels, front-rated to IPX6, and accept a 600 W dual-frequency sounder at 50 and 200 kHz. The same chassis takes radar input and shares it, so any unit on the network can control and display the radar through the KM-Router.

Numbers Behind the Glass

KM-8 measures 187×288×79 mm at 2.5 kg, KM-12 268×365×75 mm at 3.0 kg. Both draw 1.0 A at 12 V in base form and 1.5 A in C or X form, on 10.5 to 30 VDC. The GNSS engine tracks 50 channels with a 29-second cold start, and the display keeps working from -15 to +55 °C while the antenna takes -25 to +70 °C.

Where the Pair Earns Its Keep

Trawlers want the sounder at the helm and the chart by the window, the classic chart plotter and fish finder split; sport boats want radar on the main screen and AIS at a second station. NMEA 0183, NMEA 2000, Wi-Fi, HDMI and Ethernet are all present, so engine data, autopilot and a repeater join without a black box. Radar overlay on the chart remains the feature crews keep switched on in fog.

Experience: The Second Station Is the Point

The practical test for a chart plotter and fish finder installation is whether the person at the second helm can see what the skipper sees. With shared radar and sounder they can, and the conversation stops being 'what is that echo' and becomes 'hold this course'. Twelve thousand waypoints, thirty routes and an 8,000-point track log carry a season of marks without housekeeping.

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