North Chennai covering about 10 km to protect the port from seaside from similar natural calamities. The beach is planned within the port's territory before the east breakwater on the seaside and would not be accessible to the public. In addition, the port is also planning to reclaim the land adjacent to the Cooum during the Tenth Plan. On the flip side, the disaster has made the port the deepest on the east coast. A bathymetry survey conducted by the National Institute of Ocean Technology (NIOT) to measure the depth of the sea has revealed the entry channel to the port has deepened enabling the berthing of vessels of deeper drafts. The high current generated by the tsunami waves dredged about 0.4 to 0.5 million cubic metres of sediments, which has deepened the 17.4 m-deep harbour by 1 to 2 m more, especially along the Dr. Ambedkar Dock and the Barathi Dock. Similarly, the depth of the entry channel, which was 18.6 m, has deepened by a metre. Lights and lighthouses There are both historic and modern lighthouses in and around the port, some of which have been decommissioned. The port is the location of one of Chennai's earliest lighthouses—the entrance channel tower. The 24 m (79 ft) tall tower with a focal plane of 26 m (85 ft), flashing white, red and green lights, is located north of the port. It is visible only from around the entrance channel. This tower is still active. However, the first lighthouse of the city is located just outside the port, in Fort St. George campus. It was active from 1796 till 1844. The second and third lighthouses are located in the Madras High Court campus near the port. The present lighthouse is located about 6 km south of the port on the Marina Beach. It is a 46 m (151 ft) tall, 11-storied triangular cylindrical concrete tower with lantern and double gallery, attached to a 3-story circular harbour-control building, emitting light from a height of 57 m (187 ft) from the mean sea level. This lighthouse, which is active since 1977, is powered by a 440V, 50 Hz main supply. The future A third box terminal has been approved by the Cabinet Committee on Infrastructure. This will require investment of US$800 million and will be offered as a build-operate-transfer project, as part of a 30-year concession. Construction will take seven years to