Tides, Water levels, etc. http://co-ops.nos.noaa.gov/

The Coastal Engineering Page http://www.coastal.udel.edu/coastal.html

Dredging Calculations http://www.wes.army.mil/el/dots/doer/tools.html

Coastal/Hydraulics Laboratory, Waterways Experiment http://chl.erdc.usace.army.mil/