This report on global monitoring of water-related eco- systems builds on these key messages, emphasizing the value in monitoring and reporting target 6.6 pro- gress through indicator 6.6.1, while considering the current state and trends of the world’s water-related ecosystems. The report presents the rst collection of country results that were gathered during the pilot testing of the indicator 6.6.1 methodology, including the use of globally available data from Earth observa- tions, and outlines how the methodology has evolved through its piloting phase, documenting the lessons learned from country outreach activities into an In- ter-agency Expert Group on SDGs (IAEG-SDG) Tier II indicator methodology.