Notus has been a major supplier of wireless trawl and seine monitoring systems since the 1992. Customers have a choice of over 24 different sensors including door spread, trawl wire lengths, bottom contact, etc. For the past 5 years, Notus has been developing a sensor that will revolutionize the way many of its customers fish. Introducing the Notus Net Sounder.

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The Mantis Sounder uses the most up to date technology for fish detection and wireless data transmission.  This coupled with a reasonable price point and removable battery makes the sensor a necessity on many vessels.  The system consists of a receiver/computer in the wheelhouse connected to a hydrophone mounted in the hull.  This shipboard equipment communicates wirelessly to a sensor (picture to the left) mounted on the trawl.  A sounder image of fish entering the trawl and footgear clearance is transmitted back to the vessel wirelessly.

For fish detection, the Mantis uses sophisticated dB logging.  This allows Notus to harness the power of the computer for fine tuning the sounder image.  From a practical standpoint, this means the Captain can adjust the sounder gain while the Mantis sensor is on the trawl.  To ensure a stable link to the vessel, the sensor uses the well proven and robust FM modulation method.

The most common complaint with any net sounder is battery life.  Notus has responded by using high capacity NiMh batteries (14v) in a removable pack.  Each sensor is delivered with two battery packs and a charger.  One battery pack remains on the charger.  The battery pack can be changed while the sensor is on the net as an underwater connector is used.

The Mantis provides a picture of fish coming into the trawl and detects if the footgear leaves bottom (computer display to the right).  The system offers the highest resolution on the market at 640 lines.  Sensor depth is also incorporated to allow the skipper to position the trawl to maximize catch.  The Mantis can be used as a standalone unit or be incorporated in the Notus Trawlmaster system. 

A scan is transmitted to the vessel once per second.  The Mantis can also be turned off and on while fishing which gives the Captain unprecedented control over battery life.Systems have already been installed in: Canada, the USA, Brazil, Spain and Peru.  

For more information, please contact: Notus, Tel: +1 709 753 0652, notus@notus.ca, www.notus.ca or visit us at Danfish 2019, booth A137

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