This is a nice one. Shipwreck Coda Octopus Echoscope
Excerpt.. It's not just used for shipwreck hunting and mapping: Lockheed Martin uses it for subsea inspections on oil and gas operations. It helps demystify the ocean floor...whether that's a long-lost shipwreck or, someday, the lost city of Atlantis. [NOAA via Wired]