Trials of the Predator Subsea Dredger, which can move one tonne of rocks on the seabed per minute, have exceeded all expectations in terms of efficiency and performance.

The Underwater Center is a purpose-built subsea training and trials facility and is based on the shore of a seawater lake, Loch Linnhe, well sheltered by the surrounding mountains.

Nine tonnes of 50-60mm rocks were placed on areas of the seabed to recreate a range of terrains typical of the offshore subsea environment to be dredged during the trial, and the task was completed in between eight and nine minutes.

Further trials designed to test the integrity of the system, including the dredging of 100-130mm rocks in an attempt to break the machine and to identify any weak spots, highlighted the robustness and strength of the product.

A final test of the agitator system, which shoots out jets of water at the suction head end directly onto the seabed, breaking up the peat at the bottom of Loch Linnhe and dredging it at the same time, worked exceptionally well and did not affect the performance of the dredger. It can also be reconfigured subsea, with the use of a second work class ROV or diver.