Maps, glorious maps

I've commented before about how much I love maps, so I was delighted to find the new Bottom Billion Blog to have posted an interesting map of undersea high speed internet fiber network. They then followed up with a few older maps of communications lines that suggest the routes used today are well correlated with past routes.

It is interesting to compare though the lack of access East Africa gets today to the telegraph lines they once received through the Indian Ocean. Jim Cust notes that today "East Africa remains wholly unserved, instead reliant on expensive satellite connections making broadband connections out of reach of many small businesses and individuals", but upon close inspection, once upon a time it was not so cutoff.

The difference is that telegraphs could not get through without a line way back when, but internet today can get through by satellite. I wonder if the reason for the lack of lines to East Africa then is because of cost, or is something else in the way?