Odd to get downvoted for suggesting this is interesting.

1) If China feels it necessary to fabricate sightings in order to mollify its population (also note the way it has tried to manage the bereaved families and focus their anger on Malaysia including providing coordinated t-shirts etc.) then that's interesting.

2) If China, not usually noted as outstanding in air, naval, or orbital surveillance capability is able to outperform Australia (which is both very experienced with ocean searches and is operating on its doorstep) and the US then that's interesting.

3) If China is more willing to reveal its capabilities than the US or Australia that's also interesting. (E.g. I suspect the reason the Australians were so willing to commit to the current search area based on one satellite image is because they actually tracked the flight via Jindalee, but were unwilling to reveal that system's capabilities given there weren't going to be any survivors.)

China is heavily involvement in this search as most of the passengers [~150 of 230] were Chinese.

I assume this search is coordinated and everyone knows the area one ship can cover. That way the same area isn’t examined twice. Wouldn’t it then be simply up to luck as to who finds something?

You can always argue about who sent the most ships and who covered the most ground, but some nation’s ships finding this is not direct evidence for this. I would assume it would be better to determine this directly, not indirectly.

The Chinese also spotted debris on satellite imagery (on an area that had been thoroughly searched) as well as a "sea floor event" (a week after the claimed event) in the South China Sea. I wouldn't jump to the conclusion that this newest finding is an instance of effectiveness just yet.

edit: whoops, 'peeters posted just as I did

How effective have they been? So far China has found absolutely nothing.

If anything, they have been overly enthusiastic to quickly report partial results based on incomplete or bad analysis, which then turned out to be nothing at all.

I'm not sure you can generalize that. It was a Chinese agency that "mistakenly" posted those misleading satellite images, while the U.S. was the first to draw a connection between satellite data and the Indian Ocean as a possible crash area.

There have been mistakes, false leads, and promising revelations across the board.

That's just post hoc fallacy. There are a lot of vessels searching from a lot of different countries. Whoever gets lucky is going to seem more effective, but luck is probably a majority factor in this case, given the size of the search area.

These same tow sensors and underwater autonomous vehicles are used for submarine hunting. Guess which country has a large number of nuclear submarines? US does. Its expected China would try search for our subs.

Is the Chinese search part of the Australia-led search effort (i.e. the Chinese vessels are searching areas they are being tasked), or are they doing their own independent search?