The U.S. Coast Guard has finished mapping the Titan submersible's accident site and started an investigation into the implosion that killed five people that could ultimately recommend anything from new regulations on deep-sea diving to criminal charges for authorities to pursue.

A Marine Board of Investigation, the highest level of inquiry within the Coast Guard, convened Friday and is in the early stages of its investigation, officials said during a Sunday news conference. The board will publish a public report that will include safety recommendations regarding submersibles, which many experts say could use tighter regulation.

Coast Guard Capt. Jason Neubauer will head the MBI's inquiry into why the submersible imploded while descending to the Titanic wreck site in the North Atlantic - and what can be done in the future to avoid death.

"The MBI, however, is also responsible for accountability aspects of the incident, and it can make recommendations to the proper authorities to pursue civil or criminal sanctions as necessary. However, any subsequent enforcement activities wouldn't be pursued under a separate investigation," Neubauer said.

The board has started salvage operations and interviews, including with the crew of the Polar Prince - a Canadian-flagged vessel that Titan launched from - owned by Miawpukek Horizon Maritime Services.

In a statement after the Coast Guard investigation was announced, Horizon Maritime told The Washington Post that the company is cooperating fully with authorities and won't comment publicly.

John Risley, who is on Maritime Horizon's board of directors, said Friday that he believes there will be lessons to learn from the incident but said he couldn't speak for the company.

"Once people have got an opportunity to get their feet back on the ground and deal with the emotions that are probably running very high at the moment, we'll have a think about this and determine exactly what it is that we've learned," Risley told The Post. "The Coast Guard will do that. Everybody involved will do that."

Risley also said he felt the Titanic wreck site should not be visited by deep-sea divers.

"I just see the Titanic as a gravesite that should be honored, not as a curiosity," Risley said. "It was a tragic event for a huge number of people and their families."

Neubauer said the MBI will not release evidence during the investigation. However, the board will interview witnesses and key people involved during questioning that will be open to the public.

The Coast Guard only convenes an MBI for serious maritime incidents, such as the Deepwater Horizon's ecologically catastrophic oil spill and the cargo ship El Faro's sinking that killed 33 people in 2015 during Hurricane Joaquin.

The MBI probe of Titan's implosion will delve into whether "an act of misconduct, incompetence, negligence, unskillfulness, or willful violation of law" contributed to the deaths, according to the Coast Guard.

Neubauer said the final report will be sent to other involved countries' agencies along with the U.N.'s maritime policy arm, the International Maritime Organization, "to improve the safety framework for submersible operations worldwide."

The passengers aboard Titan included OceanGate CEO Stockton Rush, 61; British aviation businessman Hamish Harding, 58; retired French navy commander Paul-Henri Nargeolet, 77; and British Pakistani businessman Shahzada Dawood, 48, and his 19-year-old son, Suleman.

Risley said Wendy Rush, Stockton Rush's wife, and the wife of Dawood were on the Polar Prince throughout the search effort. Risley said Stockton Rush had once invited him to go on one of Titan's expeditions, but he declined because he said he is claustrophobic.

There weren't many regulations around OceanGate's dives to the Titanic because the operations were performed in international waters, outside any one country's jurisdiction.

OceanGate has also been criticized by others in the submersible community for not submitting Titan to a classification process, which is voluntary but standard in the industry. The process works with submersible manufacturers from the design phase and continues to inspect the crafts while they are in use.

Rush, who was piloting Titan during its final descent, had previously argued that regulations had a tendency to stifle innovation, and OceanGate argued on its website that the classification process was unnecessary.

But experts for years had warned that 22-foot-long Titan's nonstandard oblong shape and carbon fiber composite was too dangerous to take repeated dives to the ocean floor. Most deep-sea submersibles are made of a contiguous material, like titanium, and use a sphere shape that provides less space for extra passengers.

U.S. Navy officials said that acoustic sensors detected the likely implosion of the Titan submersible soon after the vessel lost contact with its mother ship on Sunday, according to The Post. The government has spent about $1.2 million to date, per a preliminary government estimate and research from The Post, to look for the submersible.

A remotely operated vehicle first found debris from the submersible about 1,600 feet from the bow of the Titanic, officials said. The search team later found the front and back portions of the pressurized hull, and analysts say the debris field indicates the submersible likely imploded before reaching the ocean floor.

OceanGate sold $250,000 tickets to bring people 2.5 miles down to the ocean floor to see the wreckage of the Titanic, where the pressure is 400 times the atmospheric pressure that humans experience on earth.