REX before being deployed to document hydrothermal vents in Iceland.

REX before being deployed to document hydrothermal vents in Iceland. Credit: Adrian Glover

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The tiny robot spying on life underwater

Marine research can be a costly proposition, requiring expensive equipment operated by teams of specialists. But an underwater robot designed for policing work has made low-cost marine research possible.

Marine biologist Dr Adrian Glover tells us how REX has opened a treasure trove of opportunities for scientific observation - from hydrothermal vents near Iceland to the depths of the English Channel.

There is a part of scientific exploration that is perhaps more important than any other: the bit where all of the scientists collectively say, 'wow!'

It happens most often during the observation phase of science - in the field, boat, cave or jungle. It is the 'wow moments' that keep scientists going through the sometimes-dull data analysis, referencing and writing-up of their research.

In 2010, the Museum acquired a tiny underwater robot vehicle, nicknamed REX (the remotely operated vehicle for education and exploration). Since then, piloting REX has provided me with more wow moments than perhaps any other project I have been involved with.

Wow moments

Switching on our high-definition camera as we glided over the edge of the Great Bahama Canyon at almost 100 metres depth - beyond what's possible through SCUBA diving. Viewing rare and astonishingly bright sunset-cup corals just a mile from the Plymouth coast. Probing the shimmering hot water of a hydrothermal vent off the north tip of Iceland. All were incredible opportunities for scientific observation that wouldn't have been possible without REX.

Retrieving experiments on the deep reefs at the edge of the Great Bahama Canyon.

Retrieving experiments on the deep reefs at the edge of the Great Bahama Canyon, filmed by REX. Credit: Adrian Glover and Nick Higgs


And most recently, the wow moment for Dr Jenny Collier of Imperial College as she got to see the deepest part of the English Channel - a chalky bed carved out by an Ice Age megaflood some 200,000 years ago.

This was the location of the flood that separated Britain from Europe - and little REX has been there, dodging shipping lanes and battling fierce currents. Our trip was filmed as part of the Channel 4 series Walking Through Time, in which Museum scientist Dr Tori Herridge takes us on a geological tour of south-east Britain.

REX has given us a treasure trove of wow moments, many of which are catalogued on its Twitter account. But it is also a lesson in how to develop a piece of scientific equipment to do something new and interesting.

A unique perspective

REX was built by VideoRay, a company specialising in remotely operated vehicles (ROVs). Together with Dr Jon Copley, my colleague and fellow operator of REX, we have completed more than 100 underwater research trips, with REX serving as our eyes in the ocean.

Jon and I came to ROV work from our day jobs as deep-sea biologists. We are used to high-seas expeditions on 100-metre-long vessels, with teams of highly trained technicians piloting truck-sized ROVs at depths down to 6,000 metres.

In contrast, REX is 40 centimetres long and I can hold it with one hand. We can take the whole thing on a plane and deploy it to 200 metres depth from any kind of boat. And its tiny size gives an utterly unique perspective on the marine world.


You can tuck in beneath boulders and sit, quietly filming a lionfish waiting for its supper. Jewel anemones appear giant and glowing on the deep reefs off Eddystone Lighthouse. And you can descend through vertical layers of purple sulfur bacteria in Bahamian blue holes without disturbing them.

Teething problems

Low-cost vehicles like REX were designed for policing, customs and hull inspections - work that takes them into rivers, lakes, and maybe the odd dip into a sheltered harbour. They weren’t designed for doing marine biology from a drifting ship, way out at sea and in the middle of the night.

When I placed a funding bid for REX in 2010, my then Head of the Department told me it would never work. 'You will get snarled in currents and probably lose it', he said. Nevertheless, he took a gamble and funded us, knowing there was a chance he might be wrong.

In 2014 we got snarled in currents and lost the vehicle.

Going for it

Jon and I decided that we had cracked a safe and effective deployment procedure. We had been on dozens of brilliant dives. We had even figured out how to recover deep seafloor experiments with REX's tiny manipulator arm. In other words, we were confident.

We decided that the best thing to do would be to ditch our carefully figured out methods and just go for it. Soon, snarled in a vast tangle of ghost fishing nets over Plymouth's notorious East Rutts, REX was gone.

Corynactis viridis jewel anemones.

Corynactis viridis jewel anemones filmed by REX at 40 metres depth in Hand Deeps, near Plymouth, UK. Credit: Adrian Glover and Jon Copley


Two things saved us. First, we realised it wasn't the piece of equipment that was important - it was the concept of doing ROV work on tiny budgets and from almost any type of boat. The other was a really good insurance policy.

The beauty of working with off-the-shelf equipment is that it's just that. We bought a new vehicle with upgraded cameras, stuck some stickers on it and nobody was any the wiser.

Seeing things for the first time

Back to the present day, and our replacement REX is still going strong, allowing us to perform scientific research in areas that would normally be out of reach on our budget.

With nearly our entire team seasick as we bobbed out in the English Channel, Jenny's and Tori's eyes glowed as they finally got to see the chalky remnants of the megaflood for the first time. Another tick for REX's wow moment list - and for scientific observation.