Samples and associated geological data are held at the British Geological Survey for Maritime Coastguard Agency (MCA), Civil Hydrography Programme (CHP), Bathymetric Survey HI1451; Caernarfon Bay, Area in SqKm: 949, (21/03/2015 to 25/08/2015), Standard: IHO S44ed5 Order 1a. Contract: Medium. FY 2015/16. Contractor: MMT UK.