Re: The Repeater System
Excellent link, but to answer your question, yes the submerged repeaters/amplifiers are powered from the landing stations. In coax cables power went down the centre conductor, in optical fibre cables the repeaters are powered over the copper tube that surrounds the fibres. The power needed is pretty high and can be dangerous, especially if a trawler pulls one up and thinks it is good idea to free their gear (expensive fishing nets) by cutting the cable. They do get cut and, as mentioned in the Wiki, measurements from land can give a good idea of where to send the cable ship, the last repeater responding also gives an indication. The ship grapples the cable and makes repairs on deck.
Biting the hand that feeds IT
