In May 2012 EGS (International) Ltd was contracted to undertake a pre-construction geophysical and bathymetric survey of the export cable route of the future Walney Extension (WOW03) windfarm site. The surveyed areas were located 22-30 km north-northwest of Walney Island, UK. Survey operations were carried out in three distinct locations; Block 1 and two separate cable routes String 2 and String 3. The survey was a Part 1 Consent and Environmental survey, data gathered for which is anticipated to lead to consent for grab sampling at the proposed sites. EGS conducted a high-frequency Multibeam Echo Sounder (MBES) bathymetric survey, combined with side-scan sonar (SSS), magnetometer and seismic sub-bottom systems. A pole-mounted Kongsberg HiPAP 351P/5 USBL was used for accurate sub-surface positioning of the towed instruments.