The ocean sustains all life on our planet and is fundamental to human survival and well-being. Now is the time to RISE UP in its defense. Coral reef die-offs, collapsing fish populations and species extinctions are evidence of the escalating ocean crisis brought about by overfishing, ocean heating, acidification, pollution and multiple other stressors. They are eroding the ocean’s ability to function as our life support system. Defending its capacity to produce oxygen, sequester carbon and provide food and livelihoods for billions of people is vital. Thriving coastal areas, a resilient deep ocean, abundant nature and protected high seas will help sustain all humankind and support the culture and well-being of Indigenous peoples and coastal communities. A healthy ocean is fundamental to a healthy planet, and makes a hopeful future possible for current and future generations.