It is the first public phase of a probe that began 15 months ago into an undersea disaster that sparked international search and rescue efforts.

Unanswered questions over the Titan’s ill-fated dive have fuelled a lingering debate over safety and regulation in the world of private undersea exploration.

OceanGate, the Washington-state based manufacturer behind the craft, has faced questions over its design choices, its safety record and its adherence to regulations.

As many as 10 former OceanGate employee, including co-founder Guillermo Sohnlein, and experts in marine safety and undersea exploration, are expected to testify over the next two weeks before the Coast Guard’s Marine Board of Investigations (MBI).

MBI is the highest available level of inquiry into US marine casualties and convenes roughly one hearing per year, its chairman told reporters on Sunday.

“Out of thousands of investigations conducted, less than one rise to this level,” Jason Neubauer said.

“There are no words to ease the loss endured by the families impacted by this tragic incident,” he added.

“But we hope that this hearing will help shed light on the cause of the tragedy and prevent anything like this from happening again.”

The board, which is made up of top Coast Guard and National Transportation Safety Board (NTSB) officials, has the authority to recommend civil penalties or make referrals for criminal prosecution by the US Department of Justice.

A sprawling search and rescue mission involving four governments unfolded after the submersible lost contact with its mother ship, the Polar Prince, on the morning of 18 June 2023 and never resurfaced.

On board were OceanGate’s founder and CEO Stockton Rush, British explorer Hamish Harding, veteran French diver Paul Henri Nargeolet, the British-Pakistani businessman Shahzada Dawood and his 19-year-old son Suleman.