What damaged the Japanese oil tanker

UPDATE Nov 23, 2010: -Nov 21 (Reuters) - according to a U.S. Maritme Administration advisory issued November 1, the U.S. has concluded that a militant group's claim of responsibility for the attack was "valid". The Abdullah Azzam Brigades claimed that a member of the group had launched a suicide bomb attack on the tanker on July 28.

UPDATE Aug. 18, 2010: - 2 small ships detected near Japan tanker damaged in Strait of Hormuz
The radar data showed the small ships sailing parallel to the tanker, passing it and then turning around. They also showed that at some point, one of the ships disappeared from the radar, a move believed to indicate that it had moved to its blind spot around the tanker, according to the sources. ... Later, the UAE’s state-run news agency WAM, citing a UAE coast guard source, reported that local explosives experts ‘‘found a dent on the starboard side above the waterline and remains of homemade explosives on the hull.’‘ ‘‘Probably the tanker had encountered a terrorist attack from a boat loaded with explosives,’’ the source was quoted as saying in the report.


A great starting place to follow events maritime in general and related mysteries in particular is EagleSpeak.
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The Japanese oil tanker M. Star shuddered suddenly as it sailed the Strait of Hormuz early Thursday morning. Investigators say collision with a submarine is among the 3 leading causes.

Whatever it was that shook a 260,000-ton Japanese supertanker as it sailed through calm waters between Oman and Iran just after midnight Wednesday, it was not a freak wave.

Crew reported seeing a flash of light followed by loud sound. What caused the flash of light? If this was another U.S. submarine collision (the third in the Strait of Hormuz?) repercussions for the chain of command could be naval-career shattering at the flag level.


The eventual finding (or cover story) will have to be very compelling for several reasons...
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+ As the world's premiere navy, with superlative satellite and discrete tracking gear, the U.S. is hardly unaware of traffic through the strait, where 40 percent of the world’s tanker oil passes.
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+ After prior submarine collisions in the strait, the U.S. would be extremely reluctant to admit to another; U.S. sub COs, however, would also be even more unlikely to permit another collision. No, it will not be one of our subs this time, even if things went awry in a submarine training exercise simulating an attack on an oil tanker.
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+ Ditto the logic against a terrorist or pirate attack. Not an Iranian sub, either. Does the imploded hull plating remind of an explosion? No, well that would rule out internal explosion, too.
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+ M. Star's hull was found to be punctured about four meters above the waterline, per The National in Dubai. The newspaper also quoted a local expert as saying that a collision was not a possibility (when was the last time even a Russian submarine intentionally rammed a target?).
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+ Iran had guarded its territorial waters with thousands of floating mines during the Iran-Iraq war; some of the mines remain to this day.
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note 1
Italy exported land and naval mines both to Iraq and Iran before and during the Iran-Iraq War. Overall export value amounted to more than US $110 million. To skirt UN embargoes, the company set up a new branch abroad in Singapore, where assembled mines with Vasella components and explosive from Bofors in Sweden, for shipment to Iraq in 1982. Mines were exported to Iraq until 1986.
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note 2
In 1988, an Iranian M-08 mine made a 25-foot (8 m) hole in the hull of the USS Samuel B. Roberts (FFG-58) wounding 10 sailors and forcing the ship to seek temporary repairs in a dry dock in Dubai, UAE.
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note 3
Iran deploys a variety of non-magnetic, free-floating, and remote-controlled mines. It is suspected of taking delivery of pressure, acoustic, and magnetic mines from Russia, and negotiating with China for rocket-propelled rising mines.
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note 4
"The military utility of Shkval-type, supercavitating rocket torpedoes has been minimized by many analysts and observers. However useful this torpedo may be (besides type 'E' Shkval's ability to generate export revenue for Russia), more clandestine application is not beyond possibility. China's unguided, EM52 rocket-propelled mine is laid on the sea floor to blast surface vessels." source: Molten Eagle, Supercavitating Naval Mine Fields, 4-27-06.
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note 5
"Iran is thought to have the 4th largest sea mine inventory (around 5000) in the world behind the United States, Russia, and China. Up to 1000 of the sea mines are of the Chinese EM11 bottom-influence mine; the EM31 moored mine; and the EM52 rocket-propelled rising mine. All of these mines are of Chinese domestically produced designs, and the Chinese are the largest supplier of mines to Iran since 1998." source: Galrahn, INFORMATION DISSEMINATION, 9-25-07.
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note 6
The most dangerous mine in the Iranian inventory is probably the EM-52. As a bottom dwelling rocket-propelled mine, up to 4 can be laid by a single small boat or dhow, and dispersed properly could heavily influence the channels in and out of the Persian Gulf. source: Galrahn (ibid)
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Submarines are always silent and strange.