The Offshore Installations (Offshore Safety Directive) (Safety Case etc.) Regulations 2015 (SCR 2015) apply to oil and gas operations in external waters, that is, the territorial sea adjacent to Great Britain and any designated area within the United Kingdom continental shelf. Oil and gas activities in internal waters (such as estuaries) continue to be covered by the earlier regulations, the Offshore Installations (Safety Case) Regulations 2005, that the 2015 regulations largely replaced.