Orkney Islands Council is the Statutory Harbour Authority for Scapa Flow – a 324.5km² area of deep water and sheltered anchorage in the Orkney Islands, north of mainland Scotland, with a long history and present use by all types of shipping. This paper will provide a short introduction to the development of the IMO and EU Directive compliant Ballast Water Management Policy for Scapa Flow which was approved by the competent planning authority in December 2013. Scapa Flow is in an environmentally sensitive area, this along with best practice was taken into account when developing the Policy – which includes strict and enforceable requirements on vessels and the Harbour Authority with regards to operations, monitoring and reporting. Since its approval there have been thirty-three occasions where ballast water discharge into Scapa Flow (by various types of vessels) has been requested. The Policy requires that vessels requesting to discharge ballast water into Scapa Flow must exchange and treat (where a treatment system is fitted) on every visit to Scapa Flow (no exceptions or exemptions allowed). To date thirty-one vessels have carried out exchange and two have carried out exchange and treat – all as per the Policy. This paper will deal with the setting of an IMO compliant Ballast Water Policy through to practical application by a Statutory Harbour Authority for a period of three years from 2013 to present day – with examples of ship types, amounts, any restrictions imposed, checks and reports made. It will include – with input from the Harbour Authority’s Marine Environment Unit lead by Jenni Kakkonen –a review of the positive actions, problems, solutions and overall results obtained so far regarding taking ballast water samples from these vessels, analysing the same and recording of details. There is a continual review and reporting process with regards to the effectiveness of the Policy to the Orkney Marine Environment Protection Committee (comprising of all the relevant statutory advisors and interested groups). The paper will contain the Harbour Authority’s way ahead in order to remain compliant, maintain its knowledge base of new technologies and environmental reports – all with the continued aim of maintaining the environment and commercial sustainability of Scapa Flow as a leading port and harbour.