Blue Robotics released the Ping360 in September 2019, a mechanical, single-beam, scanning sonar for navigation and imaging. It has a 50 meter range, 300 meter depth rating, and an open-source software interface that makes it a very capable tool for ROV navigation and underwater acoustic imaging.
A recent use-case can be found here
Blue Robotics has put together an excellent guide to Understanding and Using Scanning Sonars
Priced at ~$3,500AUD + GST, contact us today for more information