Students from my alma mater have developed an autonomous underwater vehicle with remarkable capabilities. Some extracts:

The third prototype of the Autonomous Underwater Vehicle (AUV) - Matsya 3.0 was unveiled by a
team of students and faculty in the month of April. The AUV was developed by a 30-member team
from the Institute, which has worked on it since 2011.
The vehicle will represent IITB at the International RoboSub competition at San Diego, between July
28 and August 3, 2014.

The third edition of the AUV has a geolocator which indicates the vehicle's location by using its sensors. The maximum depth that the vehicle can reach has increased from 40 feet to 150 feet

According to the team, the AUV can be commercially used for defense purposes of detection and surveillance, underwater power lines, marine research, shipwreck and airplane debris reconnaissance.
Similar AUVs have been deployed by USA in the Indian Ocean for the search of the missing Malaysian Jetliner MH 370

You can read the article here: https://www.iitbombay.org/iitb_dean_acr/may-2014-newsletter/IITB%20students%20unveil%203rd%20Prototype%20of%20AUV%20Matsya.pdf