The mother of the teenager who died on the Titan submersible has revealed she gave her place to her son after the original trip was postponed due to COVID-19.

Suleman Dawood, 19, and his father Shahzada were among five people who died when the vessel imploded on a journey to view the wreck of the Titanic.

Christine Dawood told the BBC her son had been disappointed that he was not old enough to accompany them on the original trip scheduled before the pandemic.

“It was supposed to be Shahzada and I going down,” she said.

“I stepped back and gave the place to Suleman because he really wanted to go.”

Asked how she felt about the decision, she simply said: “Let’s just skip that.”

She said “both of them were so excited” and her son had taken a Rubik’s Cube with him because he wanted to break a world record.

Mrs Dawood said her son loved the famous square puzzle so much that he carried it with him everywhere and dazzled onlookers by solving it in 12 seconds.

“He said, ‘I’m going to solve the Rubik’s Cube 3700 metres below sea at the Titanic’,” she said.

The family boarded the Polar Prince, the sub’s support vessel, on Father’s Day hoping for the trip of a lifetime.

Mrs Dawood and her 17-year-old daughter Alina were still on board when word came through that communications with Titan had been lost.

She and her daughter held out hope to begin with, when they did not initially return.

“We all thought they are just going to come up so that shock was delayed by about 10 hours or so,” she said.

“There was a time…. when they were supposed to be up on the surface again and when that time passed, the real shock, not shock but the worry and the not so good feelings, started.

“We had loads of hope, I think that was the only thing that got us through it… we talked about things that pilots can do like dropping weights, there were so many actions people on the sub can do in order to surface.

“We were constantly looking at the surface.”

She said she “lost hope” when 96 hours had passed since her husband and son boarded the submersible, which indicated they had run out of oxygen.

Her daughter held out a bit longer, she said, until the call with the US Coast Guard when they were informed debris had been found.

The family returned to St John’s in Newfoundland, Canada, on Saturday, and on Sunday held a funeral prayer for Shahzada and Suleman.

Mrs Dawood said she intends to continue with her husband’s work and she and her daughter have vowed to try to learn to finish the Rubik’s Cube in Suleman’s honour.

“That’s going to be a challenge for us because we are really bad at it but we are going to learn it,” she said.

The US Coast Guard is leading an international investigation into the loss of the Titan submersible that was carrying five people to the Titanic, to determine what caused it to implode.

Captain Jason Neubauer, chief investigator, said the salvage operations from the sea floor are ongoing, and they have mapped the accident site.

The convening of a Marine Board of Investigation is the highest level of investigation conducted by the US Coast Guard, Captain Neubauer said.