Kevlar, or something similar to Kevlar? There seems to be varying reports.
http://www.independent.co.uk/life-style/gadgets-and-tech/news/google-using-superstrong-material-to-protect-underwater-internet-cables-against-shark-attacks-9671177.html
"The fibre optic lines under the Pacific are being wrapped in a super-hard material similar to Kevlar, which is used to make bullet-proof vests and military armour."
Biting the hand that feeds IT
