Sub-contracted through NetSurvey to provide Sonsub Survey with specialist multibeam personnel onboard the MV Grampian Surveyor for the Enagas Balearic project. The project involves the installation of two offshore submarine 20″ pipelines. A 123km pipeline will connect Ibiza to the Spanish mainland gas supply network, with a second 146km pipeline connecting Ibiza and Mallorca. The maximum water depth along the pipeline routes was 1000m. As-laid surveys of the pipelines were conducted using ROV mounted dual Reson 8125 multibeam systems, together with an iXsea PHINS (PHotonic Inertial Navigation System). The EIVA software suite was used for data acquisition and processing, with Fledermaus used for visualization.