Notus Trawlmaster for twin trawls



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




The spread on EACH net is provided.  Spread reduces fuel by allowing you to keep the optimal door spread.

  • Allows you to take equal bulk in EACH net.
  • Adjust vessel speed to keep optimal doorspread.
  • Indicates when the footgear is going into the mud.


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.


Middle Wire Adjustment

The middle wire adjustment is calculated to align the middle weight (clump) with the doors.

  • When the clump is ahead of the doors, the trawls overspread.
  • When the clump is behind the doors, the trawls under spread which increases gear damage.



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.
  • Indicates if you shoot too much trawl wire as the door heels over.
  • Indicates when the doors are on bottom.


Headline Height

Indicates the distance from the headline to the seafloor.

  • Indicates when your trawls are on bottom.
  • Allows you to raise/lower the headlines depending on species.




Indicates when the cod-end is full.

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


Bottom Contact

Indicates if the trawls are on bottom.

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


Clump Depth and Temperature

  • Depth sensors indicate the distance from the surface to the middle weight (clump).
  • Ensures the clump remains on bottom.
  • Too little wire out or towing too fast can bring the clump off bottom.
  • Locates fish by trawling in the right temperature range.
  • Avoid by-catch with temperature.


Grid Angle

Indicates the sorting grid angle.

  • 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 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.




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

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