Secret Hydrographic Surveys in the Spratly Islands

Admiralty chart Admiralty's Amboyna Cay American charts April Ardasier Breakers BA chart Balabac Strait Bank and Reefs Borneo British Admiralty British charts Cay Marino charts Z.15 China Sea Pilot Commodore Reef Confidential chart Cornwallis Reef Cowe Island Dangerous Ground David Hancox East edition of BA Fancy Wreck Shoal fleet anchorage French Ganges Reef Gloucester Breakers HERALD HM Surveying Ship HMS BRIDGEWATER HMS RIFLEMAN HO/BC Hydrographic Office IROQUOIS Island and Amboyna Itu Aba Jacket Jackson Atoll Japanese Hydrographer Japanese naval Japanese secret chart Japanese survey Jiao JMSA KATSURIKI located mariners Maritime Mischief Reef Nan-Sha navigational non-existent features North Danger North Viper notation Palawan Passage Paracel Islands position published reported dangers revised RIFLEMAN route Royal Navy Sailing Directions scale secret surveys Shea Shinnan Gunto SHOM Sin Cowe Island South China Sea Spratly Island survey ship surveyors Tizard Bank Union Bank USHO chart vessel Viper Shoal