It has been said on many occasions that we have mapped the Moon and Mars better than we have mapped our own planet!
The following is a very interesting article - from MH370 to the USS San Francisco, there is a need to understand and map our planet's sea floor much better than we do now!
Good link, read some of the others from that page also. A purpose-designed and mass-produced ASUV (Autonomous Surfacing Underwater Vehicle) relatively low in cost seems a much better way to map than 20 dirty great ships ploughing around for 10 years.