How do they stretch a cable that far with no performance hit?

This is in re: to “Australia’s 5,500-mile Internet connection”
http://content.techrepublic.com.com/2346-10878_11-196690-1.html

I know this will be a very newbie like question, but I’ve always wondered how they extend these cables so far? For example, Ethernet cables (cat5) have a max distance of approx. 300 ft before there is performance degradation. I understand Australia is not stretching a cat5 to Hawaii, but how is there no performance degradation with what their using? Do they use some kind of (switch-like) link every X miles?? Enlighten me. Thanks!