When Victor Vescovo's submarine hit the floor of the Mariana Trench, it sent the sediment swirling. "At bottom," the Texas businessman-turned-extreme-explorer said into his headset. "Repeat: at bottom". In a control room more than 35,850 feet (10.9 km) above, Vescovo's dive team clapped and cheered. Congratulations were in order: they had just set a record.