When you dive past 200 meters (656 feet), you enter the deep seabed—an expansive world leading down to abyssal plains, at depths of 3,000 to 6,000 meters (up to 19,685 feet). But it doesn't stop there; the Mariana Trench drops to a staggering 11,000 meters (36,089 feet). These areas, isolated in darkness and high pressure, hold unique life and key insights into Earth's geological and biological evolution.