A blue hole in the South China Sea has reportedly been discovered as the deepest known on Earth. According to Chinese state news agency Xinhua News, the “Longdong,” or Dragon Hole, was recently measured at 987 feet deep, making it deeper than Dean’s Blue Hole in the Bahamas—the previous record holder at 663 feet. A “blue hole” is an underwater sinkhole or cavern that is open to the surface. This particular hole is located near the Xisha Islands—an archipelago claimed at once by China, Taiwan, and Vietnam— in the South China Sea. Scientific researchers have not yet confirmed the findings.