Christine Dawood, the wife of British businessman Shahzada Dawood and mother of 19-year-old Suleman who both died when the vessel catastrophically imploded, thanked those who had sent cards and messages of support.

All five passengers on board the submersible, which was attempting to view the shipwreck of the Titanic, died.

"These past few days have been incredibly challenging as a family. Emotions from excitement to shock to hope and finally despair and grief," German-born Mrs Dawood said at the virtual prayer on Tuesday afternoon.

Speaking about Suleman's birth, Mrs Dawood said that when her husband held his son "for the first time, I just knew these two belonged together. His expression was like finding a long-lost companion for adventures to come.

"These two best friends embarked upon this last voyage, their final journey together."

Mr Dawood and his wife lived with Suleman and his sister in Surbiton, southwest London. Mr Dawood was from one of Pakistan's wealthiest families and was a known supporter of two charities founded by King Charles.

His father, Hussain Dawood, remembered the other three men to lose their lives on the Titan and spoke through tears at the memorial.

"In such a situation what does a father say, and a grandfather?

"Both of them [were] so excited. So terribly excited about going to see the Titanic," he said.

He added: "It's amazing that Shahzada not only exhibited a spirit of entrepreneurship but a high spirit of exploration.

"Shahzada and Suleman both convinced us that we should go to Antarctica with them this coming winter and how excited they were - an amazing father and son."

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A close friend and colleague of Shahzada Dawood said he was "always trying to challenge himself and those around him" and that his death "leaves a gaping void in my life".

"I was blown away by his thought process and vision," Inam ur Rahman said, adding that he also had "large doses of humility" and "incredible empathy".

He also remembered Suleman as "a sensible and respectful young man" who "operated at a level way ahead of his age".

The 19-year-old, a student at the University of Strathclyde in Glasgow, was planning a world record attempt to solve a Rubik's Cube 3,700m below the surface of the ocean.

His father's colleague added he hoped Suleman was "in heaven teaching the angels to do a Rubik's Cube in 15 seconds or under".

British billionaire Hamish Harding, Titanic expert Paul-Henri Nargeolet and the chief executive of OceanGate, the company that owned the submersible, Stockton Rush, were also killed in the 18 June implosion.

A frantic five-day search commenced but pieces of the vessel were found on Thursday about 487m from the wreck of the Titanic.

Mrs Dawood told the BBC she gave up her place on the Titan submersible after the original trip was postponed due to COVID.