Introducing the world’s first wireless monitoring system for scallop dredges: the
Dredgemaster. The system has been developed by Notus Electronics Ltd (Notus)
in coordination with the scallop industry. Data from one vessel indicated a 22%
increase in catch!

The Dredgemaster consists of: an acoustic receiver and computer in the wheel
house, a hydrophone and sensors mounted on the dredge (see picture).
Communication between the sensors and vessel is wireless. The system was
developed in coordination with the scallop industry. A major partner in
development was the FV Capt. Ryan from North Carolina USA. Over the last 13
months, the Captain Ryan has used the Dredgemaster. The most important
parameters measured are: warp length, pitch angle and roll angle.

Warp length is measured on both dredges and has an accuracy better than 0.5m.
Warp out is a major determinant of the dredge’s pitch angle (forward/backward
angle). Pitch determines how well the dredge fishes. For example, the FV Capt.
Ryan determined that the optimal pitch angle was 9°. Shooting just a mark too
short would result in a 14° pitch and reduced fishing. Likewise, speed of the
vessel greatly determines the dredge’s pitch.

The results of monitoring the dredges angle were clear. The FV Capt. Ryan set
one dredge according to Notus reading. The other dredge was fished “the old
way.” Data was recorded over an entire day and Notus clearly demonstrated a
22% increase.

Roll angle is also monitored which instantly detects if the dredge flips during
shooting. Other options available are: a club stick sensor, depth, dredge spread
and temperature.