Cables are mostly damaged by fishing in coastal areas (continental shelf) or by deep undersea currents that erode the polyurethane jacket that protects them. So it is crucial that the cable be buried at least one meter and preferably two meters in coastal waters. The big fishing boats scrape sea floor -  the ecological equivalent of surface or 'strip' mining. These boats scrap the ocean floor and can hit the cables or even sever them. 

And consequently, the cables themselves have thicker and more rugged cladding in the coastal waters. A thick armor in the deep sea is simply too expensive and makes it difficult to raise the cable out of the water and repair it. Too much 'tension' according to the sailors that operate the ships that lay and repair these systems.

Roderick S. Beck
Director of European Sales
Hibernia Atlantic
1, Passage du Chantier, 75012 Paris
http://www.hiberniaatlantic.com
Wireless: 1-212-444-8829.
Landline: 33-1-4346-3209.
French Wireless: 33-6-14-33-48-97.
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rod.beck@hiberniaatlantic.com
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