CIMSEC has a brief discussion of the possibility of deploying a Coast Guard presence in the South Chia Sea.
First let me say, I don’t think using cutters for Freedom of Navigation demonstrations would be an improvement. Our warships have every right to be there. Substituting Coast Guard Cutters to be less offensive to the Chinese might be seen as a sign of weakened resolve, and it would be a whole lot easier for them to make a move against a cutter than a DDG.
The presumption in these discussions seems to be, that if we do put a presence in the South China Sea, it will be a large cutter. There is another alternative. If we want a Coast Guard presence in the area, perhaps we should start small. We could move three 110 foot WPBs to a port in the South China Sea. When enough Webber class become available, we could replace the WPBs with the newer WPCs and donate the 110s to a navy or coast guard in the area. (It would not hurt if some of the members of the WPB crews were of Asian descent.)
They could do the same kind of capacity building our cutters in South West Asia do. They could help with local fisheries enforcement, particularly the increasingly aggressive members of Chinese maritime militia units. If our cutters occasionally provide force protection or operate with a DDG conducting a Freedom of Navigation Exercise, that’s good too.
Chuck Hill's CG Blog 
The Coasties are stretched thin enough already. The freedom of navigation mission in the South China Sea is and should remain a Navy mission. Yes I’m well aware of how often the USCG has been called upon to support military involvement in the international arena (e.g. Vietnam; Persian Gulf; Africa; South America etc.). But a better use of USCG assets, and in particular its larger cutters, would be to keep it within the scope of its primary missions. Here’s an idea: dedicate a National Security Cutter or a WMEC (with embarked helo) to the immigration and refugee disaster at sea in the Mediterranean. The Coasties have the equipment, the skill set and the experience to be of assistance there, and it would free up other USN assets, and certainly the DDGs, for what they should be doing.
And to be honest I would not want the USCG in the South China Sea unless they were equipped for the maritime security role in a wartime environment considering how violent the Chinese have been to the other countries in the region. But overall leave the Projection of Power displays to the Navy.
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