No longer sold

Simrad FM90

The Simrad FM90 is a flexible and feature-packed third-wire Multibeam Trawl Sonar

With a class-leading real-time image refresh rate, the FM90 provides a detailed live representation of the trawl. This fast refresh rate allows better trawl positioning so that you can maximise your catch and reduce the potential for expensive damage.

Key features

  • Real-time net picture
  • Superior bottom picture
  • Simplified software with automatic adjustments
  • Trawl and PI/PX sensor export to Serial Port or Ethernet Port
  • No dongle required to operate software
  • Convenient lift handles on Deployment Pack
  • High-visibility confirmation of Deployment Pack orientation during net launch
  • Easy access to third-wire connector
  • Fast flooding and draining of the Deployment Pack
  • No moving parts means less maintenance
  • Compatible with Simrad PI/PX catch monitoring sensors

Check out the features provided with our latest software release

The following screen capture shows a typical catch situation with the FM90 in use. In the largest window of the display you can clearly see the trawl opening and the bottom. The view on the left side shows the echogram from one of the built-in echo sounders. On the right-hand side, you can see information from the catch monitoring sensors in use.

System description

The FM90 has a fast refresh rate that allows you to view the sonar images in real time. The FM90 enables use of your existing PI/PX catch monitoring sensors. It operates equally well in the water column and close to the bottom.

The FM90 Multibeam Trawl Sonar offers many advantages over conventional mechanically-scanning trawl sonars in most applications. However, it is not a complete replacement in some applications. We recommend the FM90 mainly for surface, pelagic, and semi-pelagic trawling on soft bottom. For bottom trawling and trawling on hard bottom we recommend the FS70 Trawl Sonar.

The FM90 Sonar communicates with the vessel by means of a third-wire system using very high bit-rate digital subscriber line (VDSL2) communication, transmitting real-time images of the net opening at rapid refresh rates. In addition, an echo sounder looking up ("up sounder") monitors fish escaping over the net, while another echo sounder shows the foot-rope, the sea bottom, and the fish entering the net.

By means of the submerged Trawl Unit, the FM90 communicates with a number of Simrad PI/PX 40 kHz catch monitoring sensors by means of hydroacoustic links. Up to six measurements can be made simultaneously. Standard pitch, roll, depth, and temperature sensors are also built in to the Trawl Unit.

The FM90 is a solid-state sonar system. This design eliminates moving parts, and increases reliability and availability during fishing operations. The FM90 is backed by the product warranty and global service network offered by Simrad.

The FM90 is a unique sonar, both in design and functionality. When the FM90 sonar pings, it sends out sound energy in a 240-degree sector. This energy is reflected from the net, from fish, and from other targets in the water column. The reflected energy is received by the transducer, processed, and shown on the display. Because the FM90 pings across a wide area in one ping, the refresh rate to generate a picture of the net opening is almost instantaneous. This gives you real-time images, allowing you to adjust to very fast movements of fish schools.

The FM90 uses an updated version of Kongsberg Mesotech's tried and tested M3 Sonar® multibeam processing software, successfully deployed world-wide for many years. The software uses innovative processing algorithms to automatically optimize the image quality specifically for fishing applications. It includes FM transmissions (also known as "Chirp") to ensure a clutter-free picture with a very high resolution in range.

The FM90 Processor Unit is controlled by the Microsoft® Windows® operating system. This allows for a flexible choice of presentation modes, and for a large range of user applications.

System diagram

The system diagram identifies the main components of a basic FM90 system, as well as the connections between the units. Interface capabilities and power cables are not shown. The display is not a standard part of the FM90 delivery. This is a commercial item that can be purchased locally.


(A) Processor Unit
(B) Ethernet cable
(C) Power/VDSL Unit
(D) Third-wire or test cable
(E) Trawl Unit
(F) Aft-looking catch hydrophone
(G) Forward-looking hydrophone (Optional)
(H) 40 kHz PI/PX Sensors

System Units

Processor Unit

A dedicated maritime computer is provided with the FM90 Multibeam Trawl Sonar. The Processor Unit is normally mounted on the bridge.

The FM90 Processor Unit is a rugged and powerful computer. It is designed for long life in a demanding maritime environment. It contains the operational software, and offers the user interface that allows you to control the FM90. It also controls the interface to peripheral devices.

The Processor Unit is based on the Microsoft® 64-bit Windows 7 operating system.


Power/VDSL Unit

The Power/VDSL Unit includes both the power supply and the modem required to communicate with the Sonar Head in one box.

This unit provides power to the Sonar Head and aids communication between the Sonar Head and the Processor Unit. The Power/VDSL Unit connects to the Processor Unit and the Sonar Head with an Ethernet cable. The Power/VDSL Unit must be mounted on top of the bridge console or recessed and flush mounted into the bridge console.


Trawl Unit

The Trawl Unit is made up of several components, including the Sonar Head, enclosed in a Deployment Pack.

In addition to the FM90 Sonar Head, the Trawl Unit includes the third-wire extension whip and hydrophone(s). Mounting shackles on the Deployment Pack aid in attaching the Trawl Unit to the net. An access panel provides easy access to the third-wire whip and strain-relief block, minimizing the need to open the Deployment Pack.

The Trawl Unit contains an aft-looking catch hydrophone to communicate with your catch monitoring sensors. An optional forward-looking PI hydrophone communicates with sensors mounted on the trawl door, if you have any. The Trawl Unit is attached to the third wire, which carries sonar data to the Processor Unit.


Current software version

We recommend that you always keep your Simrad FM90 system upgraded with the latest software version.

The current software version is v1.2.1 (2018-06-07). All applicable information related to this software release can be found in the Software Release Note.

We always recommend that you keep your products upgraded with the latest software version.

Contact your local dealer for assistance. He/she can provide the software update and relevant licenses and will install the software for you. Your dealer can also provide other advice related to the use and maintenance of your echo sounder system.

End-user documentation

All public documents related to the Simrad FM90 can be accessed using the links below. The documents are provided in several formats including PDF, HTML, EPUB and/or CHM. When applicable, certain publications are available as interactive electronic technical manuals (IETM) on separate websites.

Available documents

Shortcuts to online IETM publications

Services and support

  • 24/7 Technical support

    Our 24/7 technical support team is there to help at any time, day or night, wherever your vessel is.

  • Conversions, retrofit and refit

    We understand the importance of having the right parts, available in the right place, at the right time.

  • Training

    Ensure that your crew is properly and thoroughly trained. This will reduce operational risk, downtime and maximise return on asset investment.