The above photo illustrates the final course of the Costa Concordia. It was obtained from Costa’s official vessel positioning. I then superimposed it with the last AIS data to leave the ship via MarineTraffic. Her initial course, starting from the southeast [bottom left in the photo] appears to be a shorter route to Savona, her destination.
The standard vessel route for her course and heading would be a westerly route, away from the coast. In the photo below, the blue would be the safest, less hazardous route. 
The red is her actual route and the yellow is her planned route. As you can see, sailing closer to the shore saves time and fuel, but its not without its difficulties as there are small islands and shoals that dot the path. It must be mentioned that this is not the first time she’s sailed this route. In fact, she has sailed this route many, many times before. The Director General of Costa Cruises Gianni Onorato is quoted as saying:”The ship was doing what it does 52 times a year, going along the route between Civitavecchia and Savona.”
Here’s video of her sailing unusually close to the isle where she now lays. This video is from August. What’s interesting to note is her constant blowing of the ships horn. It should be noted here that vessels tend to do this when encountering hazardous navigational zones i.e. fog banks.
Back to the first image above. You can see I added her reported speed in knots. Based on those, the following is pure conjecture. It is clear that her speed is decreasing. When the news was first reported, many reports stated that she lost power prior to the grounding.
Either way she altered course. Whether it was for no apparent reason or one to save the ship remains to be seen. It is at this moment that she started reducing speed. Now what happens between the 15.3 kts and the 2.9 kts in the first image is unknown. Turkish website Sea News offers this:
However, in a distance 7-8 nautical miles from the Channel between the island and the mainland of Italy, the ship made a course alteration, up to 20 degrees by turning the course to port side,, so to speak, heading right onto Giglio Island. And the ship passed between two rocks at the east side of Giglio Island. And as tha captaşin declares that he tried to steer the ship towards the Giglio Pier, ıt cannot be due to a rudder failure.If there is not a rudder failure, and the ship is steerable, the major question still remains:
“Why such a big ship tried to pass between two rocks, in which only small fishing ships dare to navigate?”
If this is correct, the maritime route to the AIS in terms of technique that will have emerged to explain the many points that are in need. [sic]
I have never heard of this site and am hesitant to call them credible. However they do have supporting AIS screen caps to help their claim. These are said to be taken from Turkish official AIS. These may be the most official documents we have in these early hours.
click for larger (seanews.com.tr) |
The above is purely my analysis of the situation given the evidence that is know as of writing. As more becomes available it will of course create a better, clearer picture of what transpired during the late hours of the 13th and early hours of the 14th. Stay tuned because this story surely isn’t one to be buried away.