The Million-Dollar Dive

For a team of technical divers, modern technology brings a new concept of deep exploration - the iconic wreck Britannic, possibly the greatest ever wreck dive!

July 19, 2022
Inspiration CCR diver Leigh Bishop is illuminated by submersibles on the stern of Britannic.
Inspiration CCR diver Leigh Bishop is illuminated by submersibles on the stern of Britannic.
Photographer:
Leigh Bishop, Richard Stevenson and Richie Kohler

The wreck was breathtakingly massive, a replica of her sister ship Titanic, but bigger still, and completely intact. A wreck that would become not just an iconic legend but also the Mount Everest amongst technical divers. The legend that is the Britannic, the largest sunken ocean liner on the seabed!

I circumnavigated the entire wreck riding an Aquazepp underwater scooter, breathing mixed gas from huge twin 20 litre cylinders strapped to my back. I cruised along the open and covered promenade decks, under enormous lifeboat davits silhouetted above me against the midday sun and along the seabed debris field between funnels and masts to a depth of 120m. My return from the stern took me alongside ornate teak and brass windows of stately rooms like those in the Verandah Café, built not for me, but for the Edwardian aristocracy, and now lost to the ocean. Often I’d pause to peer through a window into what was perhaps once a first-class cabin or one of the parlour suites on Decks B and C.

This dive was made back in the 1990s. I had cruised through open doorways penetrating voids of darkness, deep into the wreck. My powerful scooter light illuminating internal rooms such as the first-class lounge, the smoking room and even the remains of the ship’s gymnasium. I’d dropped into what was once the grand staircase, the darkness beckoning me deeper into the depths of the wreck.

HMHS Britannic at Mudros on 3rd October 1916 (Photo courtesy of the National Maritime Museum).
HMHS Britannic at Mudros on 3rd October 1916 (Photo courtesy of the National Maritime Museum).

The best part of two decades would pass until the centenary of Britannic’s sinking in 2016. In that time I would not even come close to a dive of this calibre; I certainly didn’t expect it to ever be surpassed.
Over the last two decades Britannic had become part of my life. I was a veteran of five expeditions, and the wreck had given me new friends – and one that I would lose to the wreck itself, succumbing to the challenge of her mysteries and taking his own Britannic path of adventure.

I had been a member of the 2003 expedition, an expedition regarded by many as the most successful in the history of Britannic exploration. The boiler rooms had been penetrated and filmed – the bulkhead watertight doors wide open, proving the historic explanation of why she sank so much faster than Titanic. The minefield laid by the Germans had been discovered, answering the question of why she sank, including the mine in question, detonated but still attached to its seabed anchoring chain.

My best friend Carl Spencer led that expedition; together we had gone on to a future expedition in 2009 for National Geographic that also carried the Explorers Club flag.
During that dive, Carl developed a problem with his closed circuit rebreather. Bailing off the unit to open circuit scuba he began to make for the surface. As his gas reserves ran low, a switch to an incorrect breathing mixture resulted in a fatal oxygen toxicity hit. I had known Carl had aborted the dive but not of his death. After six hours of decompression I surfaced to news that greatly affected my relationship with deep diving in the years that followed.

Russian submersible pilot Dmitry Tomashov sits between Richie Kohler and Evan Kovacs before a six-hour dive to Britannic.
Russian submersible pilot Dmitry Tomashov sits between Richie Kohler and Evan Kovacs before a six-hour dive to Britannic.

The year 2016 marked the centenary of the sinking of Britannic and permits were granted allowing continued exploration.
Of course it was never intended that any of the great turn-of-the-century ocean liners would end up on the seabed. As the largest vessels constructed by man at the time, none of their creators would ever have imagined their machines would come face-to-face with man’s machines of the future, a century later on the seafloor.

I had seen technology develop over the years but nothing like this. Published documentary deep wreck explorer Richie Kohler and American underwater cameraman Evan Kovacs, in conjunction with a Russian u-boat group, were about to revolutionise deep wreck diving. Free-swimming technical divers would work alongside deep submersibles and remote operated vehicles (ROVs), all of which would be filmed for a special BBC television documentary as well as a big-budget documentary. British TV presenter and technical diver Andy Torbet would join the team making his first dive to Britannic as the host of the BBC show.

After the loss of such a close friend at depth, the thought of undertaking such a dive was a kind of psychological torture. But Kohler, a great friend and diving colleague of many years, had an impeccable safety plan factored in.

The key to diver safety support would focus around the introduction of a commercial wet diving bell. Safety procedures were detailed in a 70-page standard operating procedure document. Based mainly around emergency diving procedures, the document was developed between teams from previous expeditions spanning back to the ’90s.

CCR diver Leigh Bishop is photographed on decompression with his camera.
CCR diver Leigh Bishop is photographed on decompression with his camera.

There would only be four divers in the water on any day, each utilising their own preference in closed circuit technology with the team’s diluent choice of 9/73 Trimix. An emergency bailout profile would be based on a carried three gas protocol: 13/60 Trimix; 20/30 Trimix; and 100% oxygen. All other gas would be in the diving bell – the main point for bailout at depth.

Diving bell operations would be predicated by the surface vessel maintaining a three-point mooring position keeping the bell on station. In the case of a lost mooring or a drastic shift in weather conditions during the 40–45 minutes bottom phase, the diving bell could shift from station and be beyond sight of the wreck for returning divers. Protocols for this scenario involved support by ROVs and submersibles overseeing and maintaining contact with the dive team. The submersible pilots would direct divers to an off-station diving bell in mid water.

The diving bell would become key to safety protocols. Additionally, each diver would understand PPO2 (partial pressure oxygen) and venting, verbal and light communications, buoyancy adjustments, emergency (onboard and surface supplied) open circuit gas, bell master responsibility and unconscious diver scenarios.
Any diver ascending into the open bell at depth had to confirm the PPO2 was within acceptable range before removing their CCR loop and breathing in the atmosphere of the bell. The bell, on top of the wreck’s hull at 90 metres, would house a hyperoxic atmosphere with a PPO2 in excess of 2.0!

Explorer and filmmaker Richie Kohler alongside the view from the submersible of the magnificent port-side propeller.
Explorer and filmmaker Richie Kohler alongside the view from the submersible of the magnificent port-side propeller.

While the vent gas was air, the PPO2 in the bell could be dropped by venting bailout gas into the bell or having topside pump down bottom gas. With time spent in the bell, exhaled gas from a diver’s loop would require a venting phase to prevent changes in buoyancy. Venting gas and changing buoyancy characteristics were also vital if the topside sea conditions changed.

Using a bell was a new approach to a mainstream mixed-gas project. Everything had to be considered and factored into the safety element of each dive. A diver with central nervous system oxygen toxicity or air embolism, a convulsing diver, an unconscious diver, either breathing – or worse, not breathing! Protocols extended from separated diver scenarios to no gas scenarios. Basically put, all we had to do in an emergency was get to the bell.

Run times were capped at 40–45 minutes max with scrubber durations taken into consideration. Gone were the days of my youth when I was happy to push up to an hour bottom time on Britannic and suffer the long hours of arduous ocean decompression.
All of the diving operations were supported by the ever-watchful eye of ROV control centre topside and backed up by $6.5 million dollars of submersible technology! Should anyone actually get lost on the wreck, the submersible pilots would simply hold up a directional sign with one hand whilst continuing to eat their sandwiches with the other!

The four divers who made the ‘Million Dollar Dive’, L–R: Richard Stevenson, Edoardo Pavia, Leigh Bishop and Michael C. Barnette.
The four divers who made the ‘Million Dollar Dive’, L–R: Richard Stevenson, Edoardo Pavia, Leigh Bishop and Michael C. Barnette.

The expedition restored my confidence and overcame the psychological fear of deep mixed-gas CCR diving after the tragic events of 2009. So much so that the last dive of the expedition would turn into something very special – a dive I later named ‘The Million-Dollar Dive’!

Three divers, great friends who had all shared many Britannic adventures over the years, joined me as I re-lived that great dive of the ’90s. Together with Italian Edoardo Pavia, American Michael C. Barnette and fellow Brit Richard Stevenson I made a complete tour around this massive wreck in a single dive. My lithium-powered Suex scooter piloted me alongside the others as I once again cruised the decks of the massive liner and gained a new respect for this leviathan of a shipwreck.

Watching from the comfort of the best seat in the house, Richie Kohler could do nothing other than follow in the Triton 3300/3 submersible alongside pilot Dmitry Tomashov while Russian cinematographer Sergey Machilskiy caught every frame of our amazing dive on the Red Epic 5K camera.

Dmitry’s father, Evgeny, skilfully manoeuvred his specially-built one-man minimal displacement submersible into position, lighting up scenes such as the propellers and the bow as though a Hollywood movie set. Backing up all that, the ROV filmed everything from the rear and those topside simply watched in awe!

The wreck we looked upon was man’s technological triumph of 100 years previous, at the time the largest moving object ever built. The submersibles either side of us were tomorrow’s technology. Witnessing the two creations, worlds apart but inexplicably side-by-side, felt electric.

The five hours plus of decompression to follow was of course carried out with the luxury of the bell and everything that comes with it; chocolate, sushi, assorted Haribo sweets and not forgetting courtesy of Evan Kovacs, topside piped music!

I had felt like I had been diving inside a science fiction movie, but Richie Kohler, climbing from the submersible hatch, disagreed. “Science fiction – NO! I think you will find, Leigh, that from where I sat watching, that dive you just made was Science FACT!”

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