what are submersibles, how do they communicate, and what may have gone wrong?
- Written by Stefan B. Williams, Professor, Australian Centre for Field Robotics, University of Sydney

An extensive search and rescue operation is underway to locate a commercial submersible that went missing during a dive to the Titanic shipwreck.
According to the US Coast Guard, contact with the submersible was lost about one hour and 45 minutes into the dive, with five people onboard. The vessel was reported overdue at 9.13pm local time...