location                  lat        lon         depth  
Dongsha_North_Fore_Reef   20.77595   116.78188   10     
Dongsha_E4.5              20.6998    116.9042    1      
Dongsha_E5                20.699     116.9018    2      
Dongsha_North_Channel     20.7428    116.7503    5      
Dongsha_East_Fore_Reef    20.6999    116.9228    7