Interocean’s Survey Division recently completed a project supporting Northern Divers (Engineering) Limited during installation of rock bags on an exposed section of the Centrica Storage operated subsea condensate pipeline that crosses the Humber. Working from Delta Marine’s vessel Voe Vanguard, a combination of Leica RTK based surface positioning on the tip of the deployment crane and a Coda Echoscope real-time 3D sonar system was used to map the exposed pipeline and to control the positions of the rock bags during placement. Despite the strong tidal regime in the Humber, the real-time visualisation provided by the Echoscope system allowed the working time across the slack waters to be extended, thus contributing to a successful project completed safely and ahead of schedule.