Shahzada and Suleman Dawood, Father-Son Passengers, Love Science Fiction and Travel

Like the other passengers of the missing submersible, Shahzada Dawood loved adventure.

For the British-Pakistani businessman, 48, who boarded the vessel with his son, Suleman, 19, the expedition to the wreck of the Titanic followed a yearslong passion for science and discovery, according to friends and family.

“Traveling, science, are part of his DNA,” said Ahsen Uddin Syed, a friend of Mr. Dawood who used to work with him at the Engro Corporation, a business conglomerate where Mr. Dawood is the vice chairman.

Mr. Syed said that Mr. Dawood loves Star Trek and Star Wars, and is also fond of nature, often traveling to faraway places and sharing pictures of his adventures.

“He is an explorer,” Mr. Syed said.

Like his father, Suleman Dawood also loves science fiction, according to a statement from Engro. He also plays volleyball and takes a keen interest in solving Rubik’s Cubes.

The elder Dawood’s Instagram profile is blanketed with high-definition pictures of birds, flowers and landscapes, ranging from Greenland’s ice sheet to penguins in the Shetlands to a tiny bird in London with the caption “Dance of the Sugar Plum Fairy.”

“Don’t adventures ever have an end?” Mr. Dawood wrote in a Facebook post last year from a trip in Iceland, quoting Bilbo Baggins from “The Fellowship of the Ring.” “I suppose not. Someone else always has to carry on the story.”

Khalid Mansoor, another former colleague of Mr. Dawood, said that when the two worked together, Mr. Dawood was a passionate champion for the environment. He is also a trustee at the SETI Institute, an organization that is devoted to the search for extraterrestrial intelligence.

“The situation is extremely serious,” the institute wrote in a statement on Tuesday. “We are holding out every hope for a successful rescue mission and the safe return of our brother and all those on board.”

The Dawood family declined to comment as some of them traveled to Canada, the staging site for the search, a spokeswoman for Engro said.

Shahzada Dawood and his wife, Christine, who live in Britain, also have a daughter, Alina.

“May Shahzada and Suleman return to us safe and sound,” Mr. Dawood’s sister, Sabrina Dawood, wrote in a Facebook message.

Salman Masood contributed reporting.