Notus Trawlmaster for single trawls



Are my doors trawl wires marked correctly?  Is my trawl spread optimally?  Is the trawl on bottom?  The Trawlmaster provides the answers by attaching smallest robust trawl sensors to the gear.  All information is transmitted to the vessel wirelessly.



The distance between the doors reduces fuel by allowing you to keep the optimal door spread.

  • Adjust vessel speed to keep optimal doorspread.
  • Indicates when your doors have crossed.
  • Detects when your door has fallen or is stuck.


Trawl Warp Measurement

The distance from the vessel to EACH trawl door.

  • Accurately measures your trawl wires to within 1/2 meter.
  • Avoids measuring your trawl wires on shore.
  • Indicates the adjustment in cross current to “square” the doors.


Door Angle

The heel angle (inward/outward lean) and pitch angle (upward/downward pitch).

  • Set the trawl doors for optimal spread and optimal fuel consumption
  • Instantly indicates if you shoot too much trawl wire as the door heels over.
  • Indicates when the doors are on bottom.


Trawl Door Height

Trawl door height monitors the distance from the door to the seafloor.

  • Height is critical to the successful operation of semi pelagic doors that fly very close to the bottom.
  • Equal door heights translate to optimal fishing.




Headline Height

Indicates the distance from the headline to the seafloor.

  • Add a footline slave to receive footgear clearance.
  • Indicates when your trawl is on bottom.
  • Allows you to raise and lower the headline depending on species and trawling conditions.



Indicates when the cod-end is full.

  • Only take back what you can handle onboard.
  • Prevents hauling back a trawl that is only half full.
  • Provides a better indication of exactly where the fish are in the tow.


Bottom Contact

Indicates if the trawl is on bottom.

  • Fishing is greatly reduced once your trawl comes off bottom.
  • Indicates if your speed into the current is taking the trawl off bottom.
  • If you do not shoot enough trawl wire, the trawl will not be on bottom.


Depth & Temperature

Depth sensors indicate the distance from the surface to the doors/trawl.  Temperature is measured at the trawl.

  • When mid watering, trawl depth allows you to place the trawl at depth of the fish.
  • When bottom trawling, depth will indicate when the gear is on bottom.
  • Locate bigger schools and avoid by-catch with temperature.


Grid Angle

Indicates angle of the sorting grid.

  • If your grid is not at the right angle, nothing goes to the cod-end.
  • Indicates if your grid is blocked.
  • Estimate fish volume in the codend as the grid angle tends to increase with volume.


Wingend Spread

  • Provides the distance between the wingends.
  • Keeping the optimal wing spread can be just as important as doorspread.
  • Wingspread is a critical piece of information for researchers in calculating swept area


Trawl Alignment

Indicates the alignment behind the doors.

  • Calculates the distance from the starb door to the headline and from the port door to the headline.
  • Indicates the adjustment in side current and when turning.
  • Trawl angles are also calculated to ensure gear has correct hearding effect.


Manufacturer: Notus
Product: Notus Trawlmaster for single trawls
Category: Net monitoring

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