The Notus Difference

Notus sensors boast an active, two-way communication system, not offered by other net monitoring systems.

Instead of relying on traditional one-way pingers, Notus systems ‘talk’ to each other via proven two-way protocols. Using this reliable technology, Notus is the only system to allow the Captain to control battery life and data rate.

Variable data rates: 5, 10, 20 and 60 second intervals allow for control over the battery life.

Notus is the only system to offer true, omnidirectional pattern beams in all of our net monitoring sensors. This provides a reliable and robust data link.

With Notus Activ-Omni Intelligence, achieve optimal performance, for superior results.

Pictured: Pacific Dove

ActivOmni Intelligence

Shellfish Detection

Using advanced acoustic analysis techniques, the Notus ECHO detects shellfish entering the cod-end.

The Notus ECHO offers many benefits:

  • Over a three to four-hour tow, shellfish is usually only caught for 15-45 mins.

  • See exactly where the shellfish volume is and go back over the same area.

  • Eliminates ‘water tows’ – when bringing the trawl back and the only catch is water.


The ECHO system consisTs of:

Shipboard equipment (command unit, computer and hydrophone) that communicate wirelessly to the ECHO sensor located directly on the trawl. A dynamic graphic of the tow is presented that provides images to display the shellfish below the trawl. The system uses a weather tight charger that charges while the sensor is on the grid.

ECHO can be incorporated into an existing Notus Trawlmaster Net Monitoring System or set up entirely as a stand-alone system.


The Notus ECHO system

—helps Captains determine the ‘Sweet Spot’ in a tow, allowing them to repeat tows over the areas where shellfish are located.



(General specifications)
• Distance Range: Up to 2500+ m
• Grid Angle Accuracy: +/- 0.5°
• Grid Angle Resolution: +/-0.1° Weight: 2.0 kg in water


Grid Sensor

Grate Angle and Sound are standard capabilities inside the ECHO sensor

Grid sensors indicate angle of the sorting grid.

  • A necessity on any grid.

  • If the grid is not at the right angle, nothing goes to the cod-end.

  • Indicates if the grid is blocked.

  • Estimate catch volume by monitoring downward trend of grid angle.

  • Instantly see if the grid is incorrectly rigged.

Pacific Dove@2x.jpg


• Easily see when you are catching 500 lbs/hour or 6,000 lbs/hour.

• Find the ‘sweet spot’ on the tow and target that area

• See which way shellfish are moving.

• For example, detect if shellfish are moving East-West.

• Create an ECHO fleet. Work with other vessels to map out exactly where shellfish are on the grounds. to map out exactly where shrimp are on the grounds.


Temperature and depth capabilities are optional upgrades for the ECHO sensor, to optimize each tow.

Colder water can be an indicator of larger shellfish.

Depth sensors indicate the distance from the surface to the doors/trawl.

Easily see if the trawl is coming off the bottom.