A massive search and rescue operation is still being undertaken in the Atlantic Ocean to find the missing Titan, a submersible used for charter and exploration travel – specifically to see the famous Titanic wreck, which sits 3,800 metres below the ocean's surface.

It's a race against time as the US Coast Guard noted the submersible carrying five crew, including Dubai-based British billionaire Hamish Harding, had “about 40 hours of breathable air left”, as at 9pm UAE time.

Titan, which lost contact approximately 1.45 hours into its dive on Sunday, is thought to be approximately 1,450km east and 400 miles (643km) south of St. Johns, Newfoundland.

Prior to Sunday’s incident, Titan has undergone over 50 test dives, according to its owner, OceanGate Expeditions. Titan brings divers on an eight-day expedition to see the famous wreck, which sits at the bottom of the Atlantic at around 3,800m _ or over four times the height of stacked-up Burj Khalifas.

What exactly is it like to be on board the Titan submersible?

For starters, let’s start with the name – in Greek mythology, a titan is a giant born of Uranus and Gaea. In modern times, it is synonymous with anything that is gigantic in size. But the Titan submersible is nowhere like that in terms of dimension. Its length, height and width is just 22 ft x 9.2 ft x 8.3 ft. It can carry up to 5 persons (1 pilot + 4 crew), but it only has 96 hours of “life support”, or air for five people.

For the uninitiated, it is a terrifyingly claustrophobic condition inside the Titan submersible – being cut off from the world above in a 22-foot tube with no seats, one toilet and a single window to look out into darkness in the bottom of the ocean.

Made of titanium and carbon fibre, the Titan weighs about 9,525 kg _ and one very interesting fact about the cramped vessel that can dive up to 4,000 metres is that it is operated by video game console.

Yes, the gaming console is used by the pilot to steer Titan. GPS does not work for a submersible like Titan that dives to depths. Instead, it operates by pinging back a message every 15 minutes ashore to research vessel Polar Prince that it is safe. Titan lost contact approximately 1.45 hours into its dive on Sunday.

Small but powerful

In terms of size, Titan is not gigantic, but in terms of capability, it is powerful. OceanGate Expeditions said Titan is "outfitted with state-of-the-art lighting and sonar navigation systems, plus internally and externally mounted 4K video and photographic equipment. Aside from taking researchers and divers to the wreck of the Titanic, Titan is also used for site survey and inspection, research and data collection, film and media production, and deep sea testing of hardware and software.”

Stockton Rush, CEO and founder of OceanGate Inc., noted the carbon-fibre main capsule had been co-designed with Nasa and the University of Washington and was "rock solid".

It has an aerospace-standard five-inch (13cm) thick carbon fibre hull reinforced with two domed titanium end caps. It is capable of reaching depths of up to 4,000m (13,123ft) below sea level, far more than the deepest diving US submarine - the USS Dolphin - which once reached 900m below sea level.

Sit and relax

There is definitely no way one can move around the sub, which is extremely narrow for five people. The pilot, with the gaming console in hand, along with the four passengers are required to sit on the floor.

There is a 380mm domed porthole offering a viewing point at the front of the vessel, which OceanGate says is the "largest viewport of any deep-sea manned submersible". Titan is also outfitted with the latest camera technologies to capture ultra-high-resolution imagery that will help determine the wreck's rate of decay and assess the marine life that dwells on the Titanic wreck.

It is very dark in the bottom of the ocean, and wall-mounted lamps are the only source of light on board. The walls of Titan are also heated, as conditions can become extremely cold at such depths. The ship is equipped with powerful external lights which are used to illuminate the wreck of the Titanic. Several 4k cameras are also attached to the exterior, and an exterior laser scanner and sonar are used to map the ship. Inside, the crew can view the ruined vessel on a large digital display screen, while reviewing data collected on several tablets.

A full dive to the Titanic wreck, including the descent and ascent, reportedly takes eight hours. There is only one toilet for the passengers at the front of the sub, hidden by a black curtain when in use. So, the company recommends the passengers "restrict their diet before and during the dive to reduce the likelihood” that they will need to use the toilet.

No training-required

OceanGate has made it clear on its website that passengers do not need any past diving experience to board the Titan. The company says any training needed to take part is provided online before departure. Customers are required to be at least 18 years old, capable of sitting in confined quarters for extended periods of time, and able to climb a ladder. All passengers are provided with a safety briefing and a vessel orientation session, according to OceanGate.

Passenger testimony

Back in Novermber 2021, Paul-Henry Nargeolet, a former commander who served in the French Navy for 25 years, said: "Over the past 30 years I have completed more than 30 dives to the Titanic. The bow is the most exciting part of the Titanic to see. Year after year I have seen a lot of deterioration. It isn't going faster, but you can see more of the inside of the ship as the wreck decays. Also, the mast has fallen down on the well deck.

When you see the wreck with your own eyes, it is very different than seeing it through an ROV camera. You need to see it with your own eyes," says P.H. Nargeolet, veteran Nautile submersible pilot. "You have a lot of room inside the Titan submersible. We can have five people in the sub and there is a big view port. The sub is very well done, it is simple and easy to pilot, and there is a lot of innovation in Titan.”

Nargeolet, who is also one of the current five-person crew, added back then: "How many people can say they have gone 12,000 feet into the ocean? The sub felt very solid. The sub was more comfortable than I expected. We were in the sub for 11 hours. It didn't feel anywhere near that long.”