As my question states, why is only a single Bluefin-21 being deployed underwater to scan the seabed with an area of around 40 square miles?

Why aren't multiple Bluefin-21's getting deployed when deploying multiple machines would make the search faster when everything here is a very time consuming process?

  • $\begingroup$ cost and availability, it is very expensive to deploy the thing $\endgroup$ Commented Apr 17, 2014 at 13:44
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    $\begingroup$ @ratchetfreak I would say only availability. If you deploy 1 for 10 days or 10 for 1 day, the cost remains unchanged $\endgroup$
    – Federico
    Commented Apr 17, 2014 at 14:06
  • $\begingroup$ If you deploy 1 for 10 days or 10 for 1 day, the cost remains unchanged very nice point. $\endgroup$
    – SRy
    Commented Apr 17, 2014 at 14:32
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    $\begingroup$ @Federico that assumes no other fixed costs, getting the ship supporting ship out there takes fuel and when it is there it can remain there for a few weeks and deploy several days in a row $\endgroup$ Commented Apr 17, 2014 at 14:36
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    $\begingroup$ Would you rather fly 10 AUVs to Australia, then fly them back the next day, or just fly 1 down there and let it stay a while? Shipping isn't cheap. $\endgroup$
    – fooot
    Commented Apr 17, 2014 at 20:56

2 Answers 2



Why not multiple Bluefin-21's

There is only one Bluefin-21.

The other Bluefins 12S, 12D, 9M etc are mostly for shallow water work.

Other AUVs

The Bluefin-21 is not the only commercial Autonomous Underwater Vehicle (AUV) equipped with side-scan sonar.

The US Navy has spent $20M on an order for eight Knifefish (a Bluefin-21 derivative) but these are not due to enter active service until 2017. They are for mine-detection and so (I surmise) may not be well suited to deep-ocean usage.

The Royal Navy has a number of REMUS 600 AUVs but these are not designed for use deeper than 600M

It may be that most existing AUVs equipped with side-scan-sonar are not capable of deep-ocean use.

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    $\begingroup$ Judging from the fact that they are replacing dolphins and operating from Littoral Combat Ships, I would say they are not designed for deep-water use. $\endgroup$
    – fooot
    Commented Apr 17, 2014 at 14:49

Most of capable AUVs belong to offshore drilling companies like Chevron and Royal Dutch Shell. Some are also operated by deep sea cable companies.

The various armed forces operate only a handful of these AUVs, and because they are quite expensive, not many marine science institutes have them.


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