[eitland]

> Assuming the underwater cable itself is 10 times as expensive as regular cable, its about $150 million for 9000 km.

Still sounds really inexpensive when I consider it contains a large number of repeaters and is meant to stay at the bottom of the ocean.

Edit: Forgot to write, I haven't run the numbers myself but I enjoyed your reasoning here, you put a smile on my face :

> At 5 knots, it would take about 1000 hours to lay the deep sea part of the cable. If the ship costs $50k/hour to operate, that would be about $40 million. (I have no idea what it costs to operate these ships, but Google tells me that big cruise ships cost about that much to operate, and I'd guess that a cable laying ship is cheaper).

[iptrans]

Fortunately you only need repeaters every 80 km or so, so you'd only need a bit over a hundred repeaters across the 9000 km span.

Repeaters aren't terrible expensive, so they only add a few million to the total cost.

[eitland]

Checked your profile now, I belive it :-)

[jaytaylor]

And how are potential repeater unit failures accounted for?

[iptrans]

Repeaters are designed to last for the lifetime of the cable plant. Design lifetimes are 25 years or so.

Repeater design is inherently very, very conservative because if the repeater fails, the cable fails. This results in an outage lasting days, if not weeks, as a cable ship is dispatched to the failure location.

The cable ship has to trawl for the cable and pull it up to the surface. Then the cable is cut and replaced with a new section that includes a new repeater to replace the failed one. Expensive.