A submersible used to take people to view the wreck of the Titanic has gone missing in the Atlantic Ocean, sparking a search and rescue mission.
The Boston Coastguard told the BBC on Monday that an operation to find it was under way.
It is not clear how many people, if any, were on board at the time it went missing.
Small submersibles occasionally take paying tourists and experts to view the wreck of the Titanic.
Multi day trips to the wreck cost tens of thousands of dollars and one dive to Titanic, including both the descent and the ascent, reportedly takes around eight hours.
The missing craft is believed to be OceanGate’s Titan submersible, a truck-sized sub that holds five people and usually dives with a four-day emergency supply of oxygen. Contact with the small sub was lost about an hour and 45 minutes into its dive, the US Coast Guard said.
Tour firm OceanGate said all options were being explored to rescue the five people onboard. Government agencies, the US and Canadian navies and commercial deep-sea firms are helping the rescue operation.
Tickets cost $250,000 (ÂŁ195,000) for an eight-day trip including dives to the wreck at a depth of 3,800m (12,500ft). Hamish Harding, a 58-year-old British billionaire businessman and explorer, is among those on the missing submarine, his family said.
The company bills the eight-day trip on its carbon-fibre submersible as a “chance to step outside of everyday life and discover something truly extraordinary”.
The submersible usually carries a pilot, three paying guests, and what the company calls a “content expert”. The trip sets sail from St John’s in Newfoundland. Each full dive to the wreck, including the descent and ascent, reportedly takes around eight hours.
The search has two aspects. These are a surface search in case the Titan returned to the ocean’s surface but somehow lost communications, and an underwater sonar search.
The US Coast Guard has sent two C-130 Hercules aircraft to search for the submersible on the surface of the water, and has been joined by a Canadian C-130, and a P8 aircraft equipped with underwater sonar capability.
Additional expertise to rescue the vessel will be required if it is found underwater - including the US Navy.
Canada’s defence department said that, along with the aircraft, the Canadian coast guard vessel Kopit Hopson was assisting in the search.
Horizon Maritime, which co-owns the Polar Prince, confirmed to the BBC that vessel is helping and a second vessel, the Horizon Arctic, has been sent to the site.
190,000 pounds.
How the rich spend their money,to look at some dark watery grave under the sea through a little window.And the poor get blamed if they smoke and drink too much to relieve their boring lives.
This is very sad. Maybe there was engine failure. Maybe there was a leak. I hope they are ok.
Do we care less about the loss of these merely because they are wealthy? I don’t think their financial status should matter. A lost life is a lost life. I don’t think anyone deserves to die and what a horrible way to go.
What’ poor people do to relieve their boredom has nothing to do with this.
No one forced them to go.The rich via the government are always telling us poor people how to live our lives so they obviously haven’t got any more sense than we have.
Having more money doesn’t automatically make anyone smarter. and what about the two people running the show; driver and helper? Does their financial status make any difference in all this?
Of course not!
Those missing include Pakistani businessman Shahzada Dawood and his son, Suleman as well as Hamish Harding, a 59-year-old British billionaire businessman and explorer
French explorer Paul-Henry Nargeolet is also thought to be on board, and Stockton Rush, chief executive of OceanGate, the firm behind the dive, is widely reported to be on board too
Oh dear how awful , I do hope somehow they can get them up . Thinking of them and their families . Miracles can happen remember the beautiful Thai children trapped deep inside the flooded cave . Let’s hope another can happen too .
A video from a reporter who has been on the missing vessel. He notes that there are 7 ways to return to the surface. It’s concerning if none of them worked. It could be snagged in a net or sprung a leak. He says those two possibilities are highly unlikely.
US Coast Guard update of the search with specifics. I didn’t listen to the whole thing. Too technical for me.
Sorry but to my mind if they are so rich and so damn stupid to go into one of these mini subs then one wonders how they got so much money in the first place.
Money brainless and stupidity do go together
It struck me that the sub can dive 4,000m as a maximum and the Titanic lies at a depth of 3,800m. 
