The Big Read: What about all those serpents of the sea around our coast?

But he had seen nothing like this before. Mearns was a well-known figure among the bustling fleet of local herring boats and regarded as “one of the most intelligent of the Ferryden fishermen”.

Which made his encounter 130 years ago with a mysterious monster fish – claimed by the crew, according to one newspaper report of the incident, to be a sea serpent – all the more credible.

Mearns was quite certain, added the report, that “he and his crew were not mistaken as to the character of the monster and that it was not merely a floating tree”.

As bizarre as it sounds – even for a nation familiar with tales of a monster lurking in Loch Ness – the sea serpent of 1891 was not the first, nor the last, to terrorise the north-eastern Scottish waters.

Earlier this month, Nessie notched up her seventh “official” sighting of the year when a tourist from Cambridge claimed they had witnessed a large hump emerge from the inky waters of the loch.

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Looking like a turtle’s back – black with a tinge of green – it appeared in the bay close to Urquhart Castle before disappearing below the surface.

It became number 1137 on the Loch Ness Monster Sightings Register, which began with the first in 565AD when St Columba was said to have chased a sea beast from the loch.

It includes dozens of incidents that emerged during the early 1930s, sparking nine decades of “Nessie” headlines – often, it has to be said, at the peak of the summer “silly season”.

Yet, decades before those well-documented 1930s sightings, it was Montrose and the north-east that laid claim to being the home of Scotland’s most elusive monster.

Skipper Mearns had sailed his boat, in 1891, to about 20 miles off Montrose, and it was there his crew spotted the bizarre creature rising from the depths.

“It was about 30ft in length and had two paws which it raised out of the water alternately with its tail,” it was reported at the time.

The news was particularly intriguing for, just a few weeks earlier, there had been reports of another sighting, further north near Peterhead by the men on board the Rose And Thistle.

“Our crew saw a monster rise up from the sea when 50 miles off Kinnaird Head, which struck terror into their hearts,” said one crew member.

“Rising straight up from the water was a large body somewhat resembling the fore part of a horse, and not less than four times the height of our mast, dark looking in colour with large eyes which seemed to shine like green fire, and with a mouthful of white teeth, which in the declining sun shone like a white wall.

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“We were all struck with fright.” There had been countless other sightings of sea serpents and monsters before then: in 1885 a number of men “well known in Kirkwall and whose veracity is beyond suspicion” were fishing when a creature more than 100ft long, round and covered with brown hair, emerged from beneath the waves.

Well before then, Orkney had been at the centre of another sea serpent mystery, when the 55ft long body of a creature with the girth of an Orkney pony was washed ashore at Rothiesholm Bay.

It was 1808, and the creature baffled locals and experts. Its head was no larger than a seal’s but had two blow-holes, filaments that hung down like a mane and three large fins shaped like paws and jointed.

The discovery sparked huge debate over whether it was firm evidence, at last, of a real sea serpent. Experts examined the remains, but it would be many years later that it was decided the “Stronsay beast” was probably the remains of a remarkably large decayed basking shark.

Reports continued to flood in of unusual creatures in Scottish waters. In 1898, the crew on board the sloop, Dart, claimed to have been pursued for 10 miles off Aberdeen Harbour by a creature that rose 50ft out of the water, with a green dark-coloured mane, bright green eyes and “flap-like” ears. But it was Montrose that appeared to be a favourite spot for whatever lurked beneath the north-east’s waves.

The early 1900s brought a string of claims, each more unlikely than the last – and all during the tourist season. In 1902, the bold creature was said to have leapt out of the water “like a salmon, and flew through the air, clearing the suspension bridge at one bound”.

A classic image of the Loch Ness monster.

The following year, it was terrorising 10 people on board a passing steamer, charging and lifting it 6ft out of the water, apparently. Despite efforts by one crewman to shoot it, the creature was spotted the next day luxuriating in the waters off Montrose.

By 1904 it had returned to the bridge, apparently intent on demolishing it by repeatedly thrashing against it. Sightings continued for several years, with some said to have left townsfolk Stronsay monster washed ashore, there was an idea that sea serpents were long worm-shaped creatures that went around the world.

That stops being the fashion by 1850, when it’s decided they don’t exist and instead sea monsters are long-necked creatures similar to a plesiosaurus. “A lot of the descriptions begin to match that kind of creature. But no sightings really stand up to modern interpretation.”

Instead, any remains tend to be explained. “Whales when they rot can make strange shapes. And a basking shark which has started to rot loses its lower jaw, the top of the skull stays and you’re left with a long neck, four gins and a long whip-like tail.

“That said, there are almost certainly creatures still to be discovered and it’s easy to imagine there’s something out there.”

Whilst Montrose’s monster vanished, at Loch Ness an entire tourism industry was being established. Gary Campbell, who logs every credible sighting on the Loch Ness Register, says Nessie has endured because of the quality of the early sightings and a little bit of good luck.

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“In 1933 an article appeared in the Inverness Courier of a strange spectacle in Loch Ness,” he says. “It wasn’t the first that had suggested something was there, but this was on the front page and had a terrified. However, eventually the Montrose “Messie” faded into obscurity.

According to Glen Vaudrey, author of Sea Serpent Carcases, which examines remains discovered along Scotland’s shoreline, serpents and sea monsters made regular appearances in Scottish waters.

Mr Vaudrey says: “In 1808, when the description of what had been seen.

“The editor decided it must have been a monster. The story was picked up by international press and what had been accepted by people in the area as just something that was there, became a huge story.”

He believes Nessie was aided by another large, monstrous creature. “A few weeks before that sighting in May 1933, King Kong was on at cinemas.

“Instead of a monster hanging off a skyscraper in New York, here was one living up the road in Scotland.

“The tourist industry grabbed it with open arms, and within months there were tours around Inverness. A log of all the Nessie sightings was only established 25 years ago, after Gary spotted something odd lurking in the loch and realised there was nowhere to register what he had seen. This week alone the register has received three sightings from Nessie hunters viewing the loch’s webcam – all ruled out.

“Most sightings don’t make it on the register because they can be explained – most common is that it’s a boat and sometimes its an insect. Someone has seen this massive creature on the screen, but it’s actually a midge.

“The best sightings are from people who visit a lot or are local and they know what they have seen.”