The Port of London Authority (PLA) Hydrographic Service was commissioned by DONG Energy to undertake a Multibeam Echosounder (MBES) survey at the Gunfleet Sands 3 Offshore Windfarm in the Thames Estuary. The scope and technical specifications for the survey work, was outlined in Documents nos 2575696 (Appendix 6) and 2575636 (Appendix 7) respectively and included: 1. MBES survey of 50m wide corridor along Export Cable Route between the WTG F00 and the HDD exit point [See Figure 1]. 2. MBES survey of the WTG foundations F00 and G00 (100m x 100m) and 50m wide corridor along the inter-array cable. The report in this series covers survey elements which were undertaken on 12th, 13th and 14th December 2016. The bathymetric data along the export cable has been compared to the previous PLA data from May 2016 and the pre-works survey of 2012.