It should be a surveying platform
Just so, a scientific survey. Presumably, further experiments will gradually normalize their presence at the shoal.
The research mission – which began on May 20 – involved deploying a floating platform for environmental monitoring and sampling, the Chinese Academy of Sciences’ South China Sea Institute of Oceanology said in a statement on Wednesday.
The research institute said its expedition had covered the entire shoal with the aim of collecting data on the geological evolution and physiological responses of coral reefs to environmental changes.