The CHERISH project identified a number of sites within Cardigan and Caernarfon Bays for which the project required detailed bathymetric surveys. Four main type of sites were targeted; headlands, reefs, islands and shipwrecks. Headlands included Rhosneigr, Anglesey and Dinas Dinnle; Reefs included Sarn Badrig in Cardigan Bay, Islands included St Tudwall's Islands in Tremadog Bay; and shipwrecks included 'The Diamond' in Cardigan Bay. The objectives of targeting these sites were to both further understand their evolution and to join bathymetric data with existing LiDAR and UAV data for analyses.
Multibeam surveying was to be carried out in depths <25m using the Geological Survey RV Keary which is equipped with a Kongsberg EM 2040D multibeam echosounder between the 1st and 12th July 2019. Sub-bottom profiling using a hull-mounted Edgetech CHIRP 3200 was conducted along all survey lines.