We have little information on the China diving scene. It is likely that what dive sites there are will be poor visibility due to the heavy industrial output from the eastern regions cities. The effluant and pollution pumped into the sea will drastically reduce and make the diving there hazardous. For all that, for a country the size of China you'd expect it to at least be a diving dragon when it comes to scuba diving.
Hong Kong is reputed to have some decent dive sites along with some of the manchurian regions.
It is likely that the dive sites, if any will be quiet and peaceful.
China is the home of no diving organisations that we know of.
Chile is a large country that see's chilly wintery weather in the north and more sub-tropical conditions in the south.
The trend for diving in China will likely be in groups based on a club-system. For foreigners this is likely to be difficult as travel can be restrictive due to the communist nature of the country.
Hyperbaric Chambers are available in the event of an emergency. As yet we do not have further details.