Saw this interesting article in USA Today (10 June 2011, Pg. 3) "Mighty Fight On The Mississippi - Silt buildup poses major threat on shipping channel" by Rick Jervis, USA Today, aboard the Genmar Minotaur. Photo from bridge of oil tanker and graphic on how dredge boat works. It looks like this year's floods could cause a shut down of the mouth of the Mississippi if the dredgers miss a beat. Also this link to USA Today has some good video of the dredges in action, some good shots of digital chart use, explanation on navigation problems, and a pilot type boat.
Link:
http://www.usatoday.com/weather/floods/2011-06-09-silt-mississippi-river-shipping_n.htm
