Samples and associated geological data are held at the British Geological Survey for Maritime Coastguard Agency (MCA), Civil Hydrography Programme (CHP), Bathymetric Survey HI1325; Flat Holm to Middle Grounds, Area in SqKm: 82, (08/03/2011 to 08/04/2011), Standard: IHO S44ed5 Order 1a. Contract: RRS (2006 LT). FY 2010/11. Contractor: MMT.