Portland Sonar Live Diver Trials

Last month, Commercial and Specialised Diving were at Portland Harbour to assist Sonardyne in their Live Diver Detection Surveys. Sonardyne are experts in acoustic positioning, inertial navigation, subsea communications and sonar imaging. The intruder detection systems of Sonardyne’s maritime security business is used all over the world to secure maritime assets such as ports, harbours, vessels and offshore installations.

Sonardyne’s Sentinel Sonar Head is capable of detecting a submerged diver from as far as 900m in any direction due to its 360° acoustic cover.

Sonardyne’s Sentinel Sonar Head is capable of detecting a submerged diver from as far as 900m in any direction due to its 360° acoustic cover. Of course, that distance and range is significantly reduced when upside down on the back of our dive support vessel.

The team arrived onsite and mobilised all of the diving equipment onto the dive support vessel before being briefed by the client representative. With the equipment set up the team assisted in the deployment of the sonar system into the water before steaming out 1000m due north to carry out our first trial swims. Once back onshore the Sonardyne team showed us our tracking path on their monitors with astounding accuracy and clarity – even in this busy working port.

Demobbing Sonardyne
No rest for the wicked – having just finished a 500m swim against an ebbing current, the lads were changing bottles and rechecking the gear before they had even got out of their suits

Throughout the rest of the week Sonardyne carried out their presentations to prospective clients and we continued our swims as instructed. Some questions were raised about whether or not the diver would be able to evade the system by swimming in different directions to throw off the software. But despite our best efforts, swimming in zig-zags, changing equipment, changing speed (and on one occasion attempting to meet the requirements necessary to trial a theory given by one of our team members to “swim more like a fish!”) we were unable to deceive the equipment on trial.

Portland Dive Run
Image shows a typical dive run undertaken by CSD divers.

At the end of the week, with all the presentations completed, the team recovered the sonar system and de-mobilised the equipment. All works were conducted in accordance with the client’s instructions and to their satisfaction. We would like to take this opportunity to thank our skipper for all of his efforts and expertise.