You are both right, but evansb got there first.
Spratly Island, the largest island in the group that is occupied by Vietnam. Other islands and reefs are occupied by China, Taiwan, Philippines, Brunei and Malaysia.
This whole disputed area is a maze of reefs, some not charted. It is justifiably marked on Admiralty charts as "Dangerous Grounds". The main shipping lanes are just to the west of this map, in very deep water.
Over to you, bri.