Acknowledgements 3 Quiet Sound's Leadership Committee 3 Project Funders 3 Executive Summary 4 Background 4 2023-24 Voluntary Vessel Slowdown Results 4 Acronyms 5 Background 6 About Quiet Sound 6 Underwater Noise Impacts on Southern Resident Killer Whales 7 Vessel Slowdowns Reduce Underwater Noise 8 Parameters of the 2023-24 Voluntary Vessel Slowdown 9 Geography of the Slowdown Area 10 Vessels 11 Slowdown Speeds 11 Other vessel interventions 12 Dates 12 Implementing the Slowdown 13 Communications and Engagement Plan 13 Tribal Engagement 13 Communications with Mariners 13 Participant and Supporter Recognition 14 Monitoring the Slowdown 14 Vessel Participation 14 Vessel speed participation calculated using AIS data 15 Vessel participation as reported by the Puget Sound Pilots 15 Underwater Noise 15 Whale Presence 16 Evaluation and Results 16 Industry Participation 16 Participation as Reported by the Puget Sound Pilots 16 Calculated Vessel Speed Through Water Participation 17 Recognition 19 Slowdown后参与者反馈19