Contracted by NetSurvey to provide specialist multibeam personnel onboard MTS Xplorer for the MCA Passage of Tiree Survey. The survey is being conducted as part of the Civil Hydrography Programme. This catamaran vessel is being utilised to survey up to the 5m contour, predominantly on the west coast of Mull and around the Treshnish Isles. This is a particularly challenging environment, with rocky outcrops, a complex coastline and strong currents combining to make surveying a difficult task. The vessel has been fitted with a dual Reson 7125-SV2 multibeam system, operating the latest Feature Pack 3 software. This allows full rate dual head implementation, with simultaneous pings, as well providing the ability to electronically tilt the head. QINSy is being utilised for data acquisition, with post-processing performed using Caris HIPS and Fledermaus. Upon completion a Report of Survey will be submitted to the UKHO along with the processed data to enable Admiralty Chart revisions.