Installation manual

Simrad PI54
94
851-165187 / Rev.A
Simrad recommends that hydrophone tilt be preferably 20
degrees for normal trawling. If the vessel plans to operate in
deep water the tilt can be increased to approximately 30 to 35
degrees or reduced to 10 degrees if trawling will be performed
at or near the surface. Should a vessel need to operate in both
deep and shallow waters two hydrophones be employed, each
tilted preferably 15 and 30 degrees respectively.
Theoretic penetration depth table
Tilt
Distance in meters
250 500 750 1000 1250 1500 1750 2000
10 deg 50 100 150 175 225 250 300 350
15 deg 70 150 200 250 350 400 450 535
20 deg 90 180 275 350 450 550 650 750
25 deg 120 225 350 450 600 700 800 925
30 deg 150 300 450 575 700 850 1000 1150
35 deg 175 350 525 700 875 1050 1200 1400
Theoretic penetration depths for hydrophone beams
The table shows the theoretical penetration depths for
hydrophone beams (measure from their centres) with regard to
different tilt angles and varying distances to the sensors.
Recommendations:
• Normal trawling: approximately 20 degrees
• Deep sea trawling: 30 to 35 degrees
• Shallow water trawling: 10 to 15 degrees.