Hamish Harding, a British Businessman and Explorer, Is on the ...

A crew of five people, including a pilot and four others, were on board the Titan submersible when it lost contact with its support ship during a dive to the Titanic wreckage site in the North Atlantic on Sunday.

Here are the passengers who have been confirmed to have been aboard the missing craft.

Hamish Harding, a British businessman and explorer, was among those aboard the submersible, according to Mark Butler, the managing director of Mr. Harding’s company, Action Aviation.

Mr. Harding, 58, who holds several Guinness World Records, including one for the longest time spent traversing the deepest part of the ocean on a single dive, wrote on his Facebook page on Saturday that he was proud to finally announce that he had joined OceanGate’s mission “on the sub going down to the Titanic.”

Mr. Harding is the chairman of Action Aviation, a sales and air operations company based in Dubai. He had previously flown to space on a mission by Jeff Bezos’s Blue Origin rocket company.

Mr. Harding also took part in an effort to reintroduce cheetahs to India, and holds a world record for the fastest circumnavigation of Earth via both the geographic poles by plane.

In an Instagram post on Saturday with pictures of the submersible and of him signing a flag for the Titanic mission, he wrote that the group had sailed from St. Johns, Newfoundland, Canada, on Friday, and was planning to start dive operations around 4 a.m. on Sunday.

Despite the winter being particularly hard in Newfoundland this year, “a weather window has just opened up,” he added.

British businessman Shahzada Dawood and his son, Suleman, are among those aboard the missing submersible, according to a statement from the Engro Corporation, of which Mr. Dawood is a vice chairman. Mr. Dawood is a scion of one of Pakistan’s wealthiest families, with a background in textiles and fertilizer manufacturing.

Mr. Dawood and his son had “embarked on a journey to visit the remnants of the Titanic” when contact with the vessel was lost, the statement said, asking for prayers for their safe return and privacy for the family.

Mr. Dawood is also on the board of trustees for the Search for Extraterrestrial Intelligence Institute. The organization said on its website that he was a resident of the United Kingdom, and a father of two children.