Sensor depth is essentially controlled by four factors: tow cable diameter, tow speed, deployed cable length and weight at the sensor.  The tow cable is typically a fixed factor and therefore tow speed and cable length are the main variables.

To estimate the sensor depth you can visit
http://support.geometrics.com/TowDepth.html

and run the Java Applet that will compute depth, layback and tension based on the tow speed and amount of cable deployed.  You can also add additional weight to the sensor.  Geometrics can provide additional 14 lbs lead collar weights to help depress the fish, up to 4 may be added to any G-881 or G-882 fish.

If you have deep tow requirements contact magsales@geometrics.com for more information about steel cable and telemetry systems.