Savante:
BP used the Seatrack system on a Oceaneering Mil plus equipped with Fugro Chance Survey INS,DVL LBL and USBL package. Took the Techcians about a week to build the interface, calibrate and teach the crew how to use it.
Once running worked real well while using the INS and DVL as reference. Had to wait till the INS intialized and if the DVL lost track there was some hunting in the positon hold, Heading Reference was a TSS gyro and the Depth Reference was a Paroscientific Digiquartz.
If you adjusted any of the setpoints of the thrusters you would need to readjut the seatrack.
Oceaneering has developed what we call fly by wire, effectively two more auto controllers (auto east or X axis and auto north or Y axis) using a 600khz RDI DVL as your reference over ground, the TSS as your yaw and Digiquartz as your Z axis.
Works really well with a measured performance of less then 10cm in any axis displacement. Will work on a fluxgate but the better the heading reference the better the overall performance.
No extra hardware, computers, monitors, or wires.
Hope that helps, pm me if you like.
Regards,