It led the search of Scotland’s deep oceans for nearly 30 years and allowed the “inner space” beneath our seas to be explored like never before.
The SS Explorer worked out of the government-run Marine Laboratory in Aberdeen from 1955 and was one of the last vessels to leave Alexander Hall & Co, the city’s famous shipbuilders.
While images from David Attenborough’s Blue Planet II continue to astonish , it was the crew of the SS Explorer that were able to take the first underwater photographs off Scotland by tying 35mm cameras in waterproof boxes to trawler nets.
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The steam trawler was also one of the first boats in the world to be fitted with an analogue computer with scientists turning masses of data on sea life into reams of ticker tape.
Two on-board laboratories aided further discoveries with the wood-panelled saloon, complete with a real fire, allowing for some relaxation while at sea.
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The boat is now moored in Leith Docks having twice dodged the scrap yard with hopes to turn the vessel into a floating museum given its place in Scottish maritime history.
Marine scientist John Dunn spent 49 years at the Marine Laboratory - and hundreds of working days and nights on the SS Explorer as it criss-crossed Scotland’s sea territories.
Weeks would be spent on the water with the boat skirting Iceland, the Faroe Isles and Norway to the north and Rockall in the far west.
Mr Dunn said: “The explorer was an excellent sea boat, real quality craftsmanship.
“I have been in some really, really bad weather on the boat around Rockall and in the Shetland channel, and I never felt uneasy.
“You could be sitting downstairs in the saloon and World War III could have broken out and you wouldn’t have had a clue.”
It was the boat’s build that allowed good science to happen, Mr Dunn added, with its steam power creating a quiet environment for both scientists and the marine life they were researching.
He said: “There is no point taking a scientist out to sea if they are being thrown five feet in every direction. It has also got to be quiet. Not only is the constant noise of an engine very wearing, lots of noise is also problematic if you are trying to take measurements of biological specimens.
“It is like going to study birds and instead of being in a hide you turn up in an ice cream van blaring loud music.”
The SS Explorer chiefly supported Scotland’s fishing industry in making sure the seas were healthy and productive.
Odd discoveries over time included a blue and white chequered lobster, crabs with extra claws and starfish with extra legs.
An albino haddock was recently found off Shetland by a commercial vessel, he added.
He described the seas below Scotland as “colourful” adding that developments in underwater lighting had been one of the biggest evolutions his career.
Mr Dunn said: “The equipment now, and what you can see is nothing short of magic. It is a miracle.”
The scope for advancing our understanding of what lies beneath our seas is as vast as the oceans themselves, he added.
“Our understanding really of lots of process of what is in the sea is woefully inadequate.”
Mr Dunn is due to collect a MBE for services to marine science and has been named a Polar Ambassador to encourage young people into Science Technology Engineering and Maths.
Mr Dunn said: “I have talked about our oceans as being our inner space for a long time and I use it to draw a parallel with outer space. Inner space has had nothing like the amount of investment.
“The rewards in understanding what is going on down there are immense.
“There are answers to what ails us all in the ocean, such as new medicines and new fuels. We don’t have to go to space to find them. They are on our doorstep.”