The 'merman' facing a Titanic mission
Submersible pilot David Lochridge is preparing to take paying passengers down 2.4 miles to the wreck of the Titanic.
The 45-year-old Glaswegian says he was always fated to take on the mysteries of the deep.
"I was actually born with webbed feet, and my father used to comment that I looked like a merman so I was destined for the sea," he says.
His father's prediction was borne out.
Lochridge has spent much of his adult life in marine-related jobs, including commercial diving and piloting submarines.
But he is preparing for his biggest challenge yet.
Next year he will be taking dozens of paying passengers down about 12,500ft (nearly 2.4 miles or 3.8km) to the wreck of the Titanic, 370 miles south-southeast of Newfoundland.
OceanGate, the US firm behind the dives, says more people have been into space or climbed Mount Everest than have visited the Titanic's final resting place.
The firm stresses that it is a survey expedition and not a tourist trip.
Over six weeks from next May, David will make repeated dives in a new carbon fibre submersible called Cyclops 2, designed to withstand depths of up to 4,000m.
On each trip to the bottom of the ocean, he will take three "mission specialists" - passengers who are underwriting the expedition - and a "content expert" with a good working knowledge of the wreck.
- RMS Titanic was built in Belfast by Harland and Wolff
- It was an Olympic-class ocean liner operated by the White Star Line
- In April 1912, Titanic sank after hitting an iceberg south of Newfoundland
- 1,523 people died in the disaster; 705 survived and made it to land
- Oceanographer Robert Ballard discovered the wreck in 1985
The expedition doesn't come cheap. Each one of the 54 people who have signed up for the deep dive is paying $105,129 for the privilege.
That's not a random number.
The "mission support fee" is the inflation-adjusted cost of first-class passage on the ill-fated Titanic voyage in 1912.
The adventurers range in age from 28 to over 70 and include cave divers, mountain climbers and scuba divers, as well as nine Virgin Galactic "future astronauts".
They come from around the world, including the UK, US, Australia, Japan and China.
According to OceanGate, they will take an active role in areas such as communications, navigation, sonar operation, photography and dive planning.
It won't be David's first expedition to a famous shipwreck. Last year he piloted a sub down to the Andrea Doria, a passenger liner that sank off Massachusetts in 1956, with the loss of nearly 50 lives.
But this time he will be entering unknown territory as he heads down more than 3,800m to the Titanic.
His deepest dive so far has been just under 600m (about 1900ft)
But he points out that the riskiest part of a subsea mission tends to be near the surface, rather than deep down.
"The worst things that can happen take place at shallow depths - that's where you see the biggest pressure changes," he says.
"The biggest hurdle, especially with the Atlantic, is that the weather conditions are at the beck and call of Mother Nature.
"We have a mobile subsea launch and recovery system, which we can deploy from once the sub is down at depth, so we should be out of the way of all the topside weather conditions."
He adds: "The thing is, when you are in the water in a submersible, the minute the ambient light disappears, you could be at 40m, 400m or 4,000m.
"Now obviously you have got an immense amount of pressure going against the hull but you are not actually going to feel that inside because everybody inside the submersible is at atmospheric pressure."
David estimates that it will take about 90 minutes to descend to the scene of the wreck - and another hour-and-a-half to get back to the surface.
Once down there, each team will spend several hours surveying the wreck.
David explains: "Everybody knows that the Titanic is starting to crumble. There have been reports that in the next 30 to 40 years, all it will be is a pile of debris on the seabed.
"We are not going to pick anything up. We are going to go down and look at the bow area, which is going to be main focus here."
The Cyclops 2 crew will be able to see the wreck via cameras fitted around the sub or through a viewport at the front.
The expedition team plans to produce a detailed 3D model of the shipwreck and debris field using multi-beam sonar and laser scanning technology.
It will also document the condition of the Titanic using high-definition photographs and video.
OceanGate says it hopes to return to the site each year to update survey records.
"Basically it is going to provide knowledge to the world on what is happening down there at that depth to one of the most famous shipwrecks in the world," says David.
"The bow and the stern sections are a good distance away from each other, so there is a huge debris area which has not been looked at thoroughly on the previous dives that have been done.
"We want to map where these items are for future reference."
Cyclops 2, which is currently under construction, is due to undergo pressure tests before being put through its final paces in a submarine canyon in Monterey Bay, California, later this year.
Although David is heading for deeper depths than he has ever been before, he maintains he is not nervous.
"I am very excited about it," he says. "You have to be slightly different to want to do this job day in and day out.
"It is not for everybody - just having an obsession with the sea, this is what it is all about for me.
"I couldn't see myself doing anything else."