[roywiggins]

The MH370 search used sonar, which works well underwater but has quite short range so it involved driving ships around on the surface dragging sonar arrays backwards and forwards for years.

I think this is one of the systems used during the MH370 search, apparently it can scan 192km² per day.

There are 161,000,000 km² of ocean, so you'd need at least a million days or 3,000 years to scan the whole thing, give or take.

http://www.slhydrospheric.com/prosas60_spec.html

[narag]

There are 161,000,000 km² of ocean...

Sorry if you aren't the best choice, but I had to ask someone in the thread.

Why? I mean why all the ocean?

If the purpose is to find archeological sites, most will be on the continental platform.

[hetspookjee]

_what if_ you find remains of a truly ancient civilisation on the abyssal plains. Now that would get the films rolling!

[handmodel]

That sounds extremely slow but presumably now that they've built one the cost to build 100 or 1000 would be achievable if someone (or some government) had the interest.

I would think they would need a version that doesn't need the ship nearby to scale - but would still guess this is something that will be accomplished on the order of 30 years from now.

[ge96]

Would be curious if those gliders were helpful or not/how much smaller.