it was in the eonomic zone not really territory water. as for chinese chopper near japan ship i think was 90m away 30m high. the harassing of foreign ship can be a dangerous game.
Even if it economic zone . The littoral state has jurisdiction over the EEC and "innocent passage" and "oceanography research" is allowed under the treaty of UNCLOS but snooping around submarine pen can hardly be classified as innocent passage or oceanography research
Another thing is US has not even ratified the UNCLOS agreement as of to date. So how can you derive benefit when you are not even member yet!
As to buzzing the Japanese destroyer, I believe Japan attitude can be called arrogant and self serving This kind of game has been going on all along . They do the same thing to Chinese ship or Drilling rig in East China sea.
Plus why the need to shadow the fleet?. If all they want is to observe the fleet, Japan has 100 P3C Orion plane. They can easily use it to check on Chinese fleet.
Here is the official Chinese rebuttal of Japanese whinning
China defends naval fly-bys near Japan Source: Global Times [01:33 April 28 2010] Comments By Li Jing
Beijing's new ambassador to Tokyo rejected a Japanese protest Tuesday over Chinese military helicopters twice making fly-bys near Japanese naval destroyers, blaming Japan for the row, AFP reported Tuesday.
The helicopter fly-bys took place near Japan's Okinawa island this month - on April 9 and 21 - when Japanese naval ships spotted and followed the largest Chinese flotilla of warships so far to sail between Japanese islands.
Cheng Yonghua, the new ambassador, said China's naval drills in the waters off Japan are conducted "in accordance with international rules," adding that China is devoted to boosting transparency regarding its military buildup by releasing a defense white paper and through other means, according to the Kyodo News Agency.
"How would the Japanese people feel if there was a Japanese drill and the Japanese left port and were then annoyingly chased by Chinese destroyers? That breaches the spirit of mutual understanding and mutual trust," AFP quoted Cheng as saying at the Japan National Press Club.
Tokyo has lodged a protest through diplomatic channels over what it considered "dangerous" approaches by Chinese vessel-borne helicopters toward Japanese destroyers, which were said to be deployed for surveillance of Chinese vessels.
According to Kyodo, though China has explained to Japan that the approaches were a "necessary defense measure" in response to Japanese surveillance activities, Foreign Minister Katsuya Okada said Friday that he was "not convinced" by the explanation.
"Japan is overreacting on this issue," Peng Guangqian, an expert at the PLA Academy of Military Science, told the Global Times. "Those Chinese Navy vessels were carrying out normal military drills on the high seas rather than other locations. Japan needs to maintain a proper stance toward other countries' normal military exercises held there."
"This incident also indicates that China and Japan have not set up firm mutual trust. Both sides need to be devoted to strengthening the bilateral relationship further in a bid to decrease unnecessary misunderstandings and conflicts," Peng added.
Cheng was also asked to comment on an ongoing row between the US and Japan over where to relocate an unpopular US airbase on Okinawa.
"China is not in a position to comment, but the military arrangement between Japan and the US should not be aimed against a third country. … I mean China," the ambassador said, according to AFP.