Search and rescue efforts to locate a missing submersible with five passengers inside has become a recovery mission after the US Coast Guard determined there was “a catastrophic loss of the pressure chamber” following finding debris in the search area in the North Atlantic ocean. The deep-sea vessel, called Titan, lost contact with the surface on its way down to view the Titanic shipwreck, a voyage that has become increasingly popular among wealthy tourists.But more than five years ago, industry bodies raised concerns about the safety of the vessel with the company that designed it, warning its "experimental approach" to the expedition could have "catastrophic" outcomes.Today on the Sky News Daily, international correspondent John Sparks reports from the centre of the recovery operation effort in Newfoundland, and Rear Admiral Dr Chris Parry offers an insight into the largely unregulated industry of underwater submersive vehicles.Podcast producers: Soila Apparacio and Sydney Pead Editor: Adam Jay