MANAGING UNDER-KEEL CLEARANCE

Under-keel clearance became a critical factor in safe and efficient navigation when modern tankers and cargo vessels became so large that they could not enter U.S. ports except near times of high water. Because inaccurate determination of under-keel clearance can have serious safety and/or economic consequences, many ports provide guidelines for minimum under-keel clearance in their navigation channels. This article describes efforts to better manage under-keel clearance and focuses on new technologies that increase the ability to accurately predict these clearances and, thereby, allow more cargo to be transported more safely.