Playing Hide-and-Seek! With an Oil Tanker.

Supertankers loaded with crude have been making the news recently, mostly because they can't find a place to sell the stuff. These tankers departed from Kurdistan, but Iraq claims the oil they carry is their property and the Kurds don't have the right to sell it.  This global political dispute is playing out on the water in an interesting, albeit risky, way: the tankers are unable to come into port, so are lingering offshore, fully loaded, waiting for some kind of resolution.

Late in July, we tracked the tanker United Leadership as it roamed across the Mediterranean and loitered in the Atlantic off the coast of Morocco.

Now we're following one that's a little closer to home:  the United Kalavrvta has been parked in a holding pattern in the northern Gulf of Mexico about 50 nautical miles southeast of Galveston. A few days ago Reuters noted that the tanker had "disappeared" from satellite tracking data, speculating they may be trying to offload their 42-million-gallon cargo of crude onto another vessel.  The US Coast Guard weighed in with this comment: 

A Coast Guard official said the vessel in the Gulf of Mexico might have turned off its beacon, sailed beyond antennas that monitor transponders, or perhaps some antennas might have been taken out of service.

Um, that's not quite right: tankers are required by international maritime law, AND by US Coast Guard regulations, to continually broadcast their position, heading, speed and other information using a Class A AIS system when they are between ports. There should be no threat of piracy in the US Gulf of Mexico, so the captain has no legal justification for turning the system off, until the vessel is safely in port.  Which it is not.  And the AIS signals sent by the relatively powerful Class A transmitters on tankers and other large cargo vessels are readily picked up by AIS satellites, which can cover the entire ocean.  If the captain turned off his AIS, perhaps the US Coast Guard needs to go pay him a visit and enforce US law.  

So where is the United Kalavrvta?  Right where it's been for weeks, since it showed up on July 27.  See below for the details: our vessel-tracking expert Bjorn prepared this series of maps and info yesterday, using our satellite AIS data feed from exactEarth.  We hope the Coast Guard can make use of this to resolve the inconsistencies in broadcasting by this loaded supertanker.  After all, it's hurricane season in the Gulf, and a fully loaded tanker that is not broadcasting its location to all the vessels in the vicinity is a hazard to navigation, and a potentially colossal environmental disaster waiting to happen.  
--
Latest Position at: 2014-09-02 19:23:57 UTC
Latitude: 28.585117 Longitude: -94.249783
Course: 252.0°

Speed: 0.0kn

The United Kalavrvta is at anchor in the same location off Galveston. They resumed AIS broadcast but with some unusually long gaps between positions. Their last position was about 32 hours ago. Between the 26th and the 28th there was a 47 hour gap, between the 28th and the 30th there was a 53 hour gap. 

AIS data track showing path of United Kalavrvta over the past 90 days.

AIS data from September 2 showing position of United Kalavrvta at anchor about 60 miles southeast of Galveston.

Zoomed-in detail showing AIS data for United Kalavrvta since August 24; the tight circular path indicates it's anchored (probably by the bow) and drifting around the anchor point as it gets pushed by wind and current.

Just for grins, we thought we'd see if this vessel shows up on Landsat-8 satellite imagery.  The most recent cloud-free image of this area was taken on August 4.  Sure enough, the faint pattern of a large oceangoing vessel appears exactly where the AIS data say the tanker was located on that day.  

It's tough to hide a supertanker:

Part of a Landsat-8 satellite image taken on August 4, showing a vessel in the reported AIS position for the United Kalavrvta.

Detail from Landsat-8 image showing a large vessel (pale elongated blob) at the AIS position reported by the United Kalarvrvta on August 4, 2014. Vessel appears to be roughly 240 meters long. FleetMon data indicate United Kalarvrvta is 275 meters long.  This is within the error of Landsat-8 imagery, which has 30-meter pixels.  Note another, similar-size vessel at center left.