When higher accuracy is needed, we use a Trimble 5600 or Trimble S6 Robotic Total Station. The S6 has a spin rate of 115 degrees per second and a distance accuracy of +/- 0.8 mm +1 ppm.
The AQC Precision Sonar System is being deployed from a floating dock. A Trimble 5605 Robotic Total station is being used for cm/0.4" accuracy.