Millie GNotus sensors weigh just 1 kg in water which means that they do not add extra drag or unnecessary weight to the doors.
The Millie-G uses 4 1/2 foot Dunbar doors on a light single bottom trawl, and midwater doors/trawl for seasonal pelagic fishing. Working in water as shallow as 5 or 6 fathoms with wire lengths out to 175 fathoms meant an innovative approach was needed. On the doors, the Millie G monitors doorspread, wire length and door angle. Also door depth is used on the midwater gear to ensure the optimal door attitude.
The addition of Headline Height and Footrope sensors give: net opening, distance to the bottom and footgear clearance. While the catch sensor allows early detection of a good catch or an early warning of a bag of jellyfish which prove very difficult to handle on boats of this size.
Notus ‘s past experience with high length/depth scope ratios proved invaluable in getting the hydrophone installation right the first time. Nick Plant at NJP welders made an excellent job of forming the hydrophone into the glass fiber hull.
After initial shakedown sea trials, the rapid 5 second updates from the Notus system removed the guesswork from the job. The headline height was found to agree with the netmakers design and the doorspreads are responsive to the changing water depths and bottom conditions including snag detection.