Nautical Depth for U.S. Navigable Waterways: A Review,

McAnally, W. H., Kirby, R., Hodge, S. H., Welp, T. L., Greiser, N., Shrestha, P., McGowan, D., & Turnipseed, P. (2015). Nautical Depth for U.S. Navigable Waterways: A Review,. Journal of Waterway, Port, Coastal, and Ocean Engineering. American Society of Civil Engineers. 1061(10), 13.

The present state of navigation engineering knowledge concerning nautical depth in ports and waterways with fluid mud is summarized in order to examine the potential for successful application of the nautical depth concept in U.S. navigable waterways. Nautical depth defines a safe and effective channel bottom criterion in areas where fluid mud confounds conventional acoustic (echo sounder) surveying methods. Fluid mud is a high-concentration suspension which typically behaves as a non-Newtonian fluid. It occurs in ports and channels on all U.S. coastlines and accounts for a significant portion of the U.S.’s $1B dredging expense. Nautical depth has been adopted in multiple ports on three continents. Where nautical depth application is appropriate it often reduces dredging frequency and dredged material volume and can provide water quality benefits. Multiple experiments and field experience have shown that vessels can safely transit areas with fluid mud below the keel. U.S. adoption of the nautical depth concept for select ports and waterways can be expected to reduce dredging frequency and volumes. It offers potential economic and environmental benefits but will require a consensus among federal, state, and local organizations with responsibilities for constructing, operating, maintaining, marking, and using navigable waterways.