Aboard the missing sub that costs £250,000 per person, are British billionaire explorer Hamish Harding, renowned French diver Paul-Henri Nargeolet, and OceanGate founder Stockton Rush, along with Surrey-based businessman Shahzada Dawood and his son Sulaiman Dawood.
Famed writer Mike Reiss, who has worked on The Simpsons for many years, has since opened up about his personal experience with the company.
Speaking to The Sun, he said: "I have taken three different dives with this company, one at the Titanic and two others and you almost always lost communication — and you are at the mercy of weather."
He also noted his shock at how "basic and simple the whole operation is," after some likened the remote control to an "Xbox controller."
Banker Renata Rojas, who embarked on the trip last year, also lifted the lid on the communication issues while at the bottom of the ocean.
She told the publication that "you have to find a way to communicate and navigate in the bottom of the ocean. Sometimes you don’t have communications, you have maybe just one system instead of all three."
Rojas added: "Some of the lights may flicker … The battery might be low and you need to go to the surface."
The worrying incident has understandably struck up concerns about the submarine's whereabouts.