On March 4, 2023, after almost two decades of discussion, the world’s governments reached agreement on key substantive issues for a new Treaty to protect High Seas marine life. Society is starting to realize that it cannot take the ocean for granted. It contains 95% of the planet’s ecosystems and absorbs around 30% of the CO2 released into the atmosphere. But just 1 % of the high seas is governed by rules restricting human activity in the interests of protecting biodiversity and just 39% of the ocean falls under the national jurisdiction of individual countries. Having attained the High Seas Treaty, a new chapter of global ocean action is starting, opening research, sustainable development and business activities. Will there be more opportunities for young people to get involved through academia, government, NGOs and business? Challenges to be tackled relate to protecting biodiversity, predatory fishing and whether to ban deep-sea mining as a precautionary measure.