Johnson South Reef Johnson South Reef Johnson South Reef (; ), also known as Chigua Reef in China, Gạc Ma Reef in Vietnam and Mabini Reef in the Philippines is a reef in the southwest portion of the Union Banks in the Spratly Islands of the South China Sea. It is controlled by the People's Republic of China (PRC), but its ownership is disputed by the PRC, the Philippines, Taiwan, and Vietnam. Johnson South Reef lies adjacent to the Vietnamese-controlled Collins Reef (also known as Johnson North Reef) which lies to the northwest. It is naturally above water only at low tide. Prior
Osborne Reef Osborne Reef Osborne Reef is an artificial reef off the coast of Fort Lauderdale, Florida, constructed of concrete jacks in a -diameter circle. In the 1970s, the reef was the subject of an ambitious expansion project utilizing old and discarded tires. The project ultimately failed, and the "reef" has come to be considered an environmental disaster—ultimately doing more harm than good in the coastal Florida waters. In 2007, after several false starts, cleanup efforts began when the United States military took on the project. This cleanup exercise provides the military with a real-world training environment for their diving and recovery