OMMISSION OF CERTAIN NAVIGATIONAL AIDS AND WRECKS Certain lights, buoys, beacons and wrecks have been omitted from this chart; for details of these the larger scale charts should be consulted. CURRENTS The currents are influenced mainly by the winds and change according to the monsoon. For further information see Sailing Directions and Currents Atlases. Tsunami (2004) Significant changes to depth in survey areas before 2004 may have occurred as a result of Tsunami (2004). Mariners should be aware of possible changes in depth and uncharted dangers to navigation in the area.