ONWA KFish-7

The ONWA KFish-7 is a sonar-only fish finder without any navigation or structure scanning sonar. In terms of features, it can be compared with the Furuno FCV588 but has a smaller display. Although it does not have GPS and charts, it’s a fish finder that can serve you well especially at sea as it offers a superior depth range.

Key Features and Specifications

• Display: 7″ diagonal, 16 color TFT, 800V x 600H pixel resolution, LED backlight
• Transducer: KTD-520_TM
• Sonar: Dual-frequency
• Frequency and coverage:
  200 kHz / 12°
  50 kHz / 60°
• Depth range: 3,000 ft. (914 m)
• GPS: Not supported
• Maps: Not supported
• Power Usage: 12-24 VDC, 10 – 0.6 A
• Power Output: 600W
• Input/Output Data: NMEA0183

Sonar and transducer

The ONWA KFish-7 has standard dual-frequency sonar without CHIRP technology. It doesn’t offer structure scanning possibilities, such as SideScan or DownScan. It supports two frequencies, these being 50 kHz and 200 kHz.

The unit comes with the KTD-520_TM transducer which features a transom mount and 26 ft. (8 m) of cable with a 3-pin connector. The transducer supports both 50/200 kHz. It casts conical beams with a coverage of 12° @ 200 kHz, and 60° @ 50 kHz. The maximum depth range of this fish finder system with the included transducer is 3,000 ft. (914 m), which makes it ideal for bluewater fishing.

The unit has a dual-frequency mode. In other words, it can show the data from both transducer beams in split-screen. This feature can be very useful for finding fish schools with different reflection characteristics with frequency. For example, a school of small fish returns stronger echoes on a high frequency than on a low frequency.

Apart from the dual-frequency mode, this ONWA fish finder offers quite a few other useful fish detection features. One of them is Fish Marks, a function similar to the Selective Fish ID on the Humminbird fish finders. This assigns fish icons of different sizes depending on the strength of each echo, to targets interpreted as fish. Each target also has its depth next to it.

Amplitude Scope and a Zoom Mode are also available. The A-Scope feature is a vertical flasher view that shows the most recent sonar echo. It appears on the right of the screen and takes approx. 1/4 of its width. For the Zoom Mode, three displays are available, these being Marker Zoom, Bottom Lock Expansion, and Bottom Zoom.

Among other very useful features, we can count Clutter Level, Noise Limiter, Time Variable Gain (TVG), Automatic Operation, Gain Adjustment, and more. The unit also has three alarm modes, for depth, fish, and temperature. The transducer does not have an internal temperature sensor, though. So, in order to use the temperature reading, you will need to connect a water temperature sensor to the unit.

Control unit features

The ONWA KFish-7 features a 7-inch diagonal display, TFT color, with LED backlight. It has a pixel resolution of 800V x 600H. It is watertight and designed to withstand incidental water exposure with no problem.

The unit does not have touchscreen technology. You can only operate it through the keypad on its right. The keypad has multiple buttons, including Menu, Mode, +/- Shift, Up/Down Marker, Escape, Enter, Sig Lev for eliminating low-intensity echoes, Auto for the quick enabling of the Automatic mode, a Gain knob, +/- Range buttons, and the On/Off button.

The unit does not have advanced networking features such as Ethernet, NMEA 2000, or wireless connectivity. However, it does have NMEA 0183 port to which you can connect a water temperature sensor. It also does not have a microSD or SD card slot.

Finally, the box includes a tilt and swivel mount with a triangular base. The transducer comes with a transom mount. The box does not include a unit cover.

The Pros

• Low/High frequency sonar – supports 50/200 kHz;
• Dual-frequency mode;
• Transducer included;
• Can scan depths up to 3,000 ft. (914 m) – great for bluewater fishing;
• Multiple standard sonar features, including
  A-Scope, Bottom Lock, Automatic Mode, Fish Mark, Clutter Level Adjustment, Time Variable Gain, Noise Limiter, Interference Rejection, various alarms, and more;
• NMEA 0183 port;
• Tilt-and-swivel mount included.

The Cons

• No CHIRP technology;
• No structure scanning sonar;
• No sonar recording feature;
• No circular flasher feature;
• No navigation features.

Summary

The ONWA KFish-7 is a sonar-only fish finder featuring dual-frequency standard sonar and is capable of 200 kHz / 50 kHz. It comes with the KTD-520_TM transducer that supports both frequencies. It does not have any navigation features or structure scanning sonar but does offer an excellent depth range of 3,000 ft. (914 m) which makes it a great choice for bluewater fishing.