Who should pay for OceanGate's experimental approach and subsequent disaster?

The search for five missing passengers on board an experimental submersible is now over, winding down one of the largest joint search and rescue responses in American and Canadian history.

As police and officials now comb through the facts to figure out what went wrong, debates are raging over who should be responsible to pay for the massive response on international waters.

Rear Admiral John Mauger of the U.S. Coast Guard was unequivocal when asked on Sunday.

"As a matter of U.S. law, we don't charge for search and rescue nor do we associate a cost with human life," he said. "We always answer the call."

Five people are dead after the Titan submersible operated by OceanGate Expeditions imploded on the way down to see the wreckage of the Titanic last Sunday. The search spanned Monday to Friday, with hopes the crew was still alive but snagged somewhere on the ocean floor.

The law is clear — The U.S. and Canadian Coast Guards will never send someone a bill if they need to be rescued. But in the wake of a massive search involving 10 ships from four countries, constant aerial surveillance and the most advanced remote-operated vehicles in the world, experts are questioning if it's time to change the rules.

"There's been a hot debate for a long, long time about who bears the cost of a rescue operation," said Mervin Wiseman, a Newfoundlander who spent 20 years as a search and rescue coordinator for the Canadian Coast Guard in St. John's.

Wiseman said countless resources have been dedicated over the years to searching for people who set off on adventures and suffered the consequences. Those missions are expensive, and he estimates the Titan search will be north of $20 million when final costs are tallied.

"It's debatable, I know, but I think there should be some level of cost, or responsibility taken for that cost," Wiseman said.

His biggest issue isn't with money. Wiseman said people often don't consider the risk involved for the search and rescue teams that are tasked with coming to save them. In the Titan search, for example, Wiseman said the pilots of the low-flying aircraft were risking their lives daily and crews on board the ships were pushed to their limits over five days of constant searching on the brutal North Atlantic Ocean.

Wiseman would like to see explorers and adventurers have to pay a bond, to be returned if they make it home safely or if they have a comprehensive plan in case something does go wrong.

"If there's somebody out there flying by the seat of their pants with no financial wherewithal to do that, then maybe they'd forget the idea," he said.

Engineer Bart Kemper was one of the submersible industry leaders who helped develop a letter warning OceanGate Expeditions CEO Stockton Rush of the potential for "catastrophic" consequences in 2018.

The letter warned Rush against the experimental approach he was taking with Titan, and his decision to not have the submersible "classed" in a peer-reviewed process.