Down Under, they got a boost from Dutch artist called Isaac Gilsemans, on board when Abel Tasman's 1643 expedition arrived at Golden Bay.
As Tasman's two ships neared the shore, mere-wielding warriors from the Ngati Tumatakokiri tribe (later massacred by its enemies) rammed their waka into a ship's boat.
Before you could say "Moordenaers Bay", they'd bludgeoned four Dutchmen to death. Gilsemans might have been affected by this.
He created engravings of huge native warriors, towering over the Three Kings Islands, which was the expedition's next and final port of call in New Zealand.
Back in Europe, the images persuaded Europeans that - like Odysseus - the Dutchmen had indeed stumbled upon a land of giants.
And as the sun set on the dreamy Whangaparapara Harbour my companions at Great Barrier Lodge had me persuaded that Gilsemans had probably seen the real thing.
During dinner with Lodge managers Ian (Archie) and Erica Archibald and their neighbours Murray and Jan Willis, we discussed ancient giants or "guardians".
Their huge bones and artifacts are said to turn up on the island to this day.
"And", said Murray, "they occasionally appear as apparitions".
Maori had told him of seeing "the guardians" lined up on ridges at the north end of the island, but only fleetingly, during lightening strikes.
Meanwhile, a few years ago a dark-skinned woman, who was all of two-metres-tall and completely naked, had appeared at the foot of the bed of a woman visiting the island.
Jan and Murray Willis . . . the guardians still appear. Photo /
The visitor to the Barrier, staying at Medlands while working as a locum at the Medical Centre, was stunned to see the giantess vanish a few moments after first appearing.
I knew Murray was a respected electronics engineer, with a QSM for community work supported by Jan, which included setting up communications for essential services on the island.
But winding-up visiting journalists wasn't exactly unknown in these parts. A naked black giantess was a bridge too far, I told my hosts, even in the context of tall tales from the backblocks.
Was there nothing more substantial concerning these guardians? Yes, Murray was quick to assure, there was.
An island identity, the late Paddy McGeady, had come across their remains while working with a gang building a road through the Kaitoke Swamp during the 1920s.
"After draining part of the road they found in mud, lots of human skulls.
"These were at least one-and-a-half to two times the size of a human skull.
"Each one had a hole in the temple, which meant they'd been struck with a patu, which means they were probably killed as slaves."
Murray and Jan had seen giant adzes found by Paddy, and kept in a collection of artifacts by his widow, Mrs Bella McGeady.
Murray held his hands about 300 ml to 400 ml apart, to demonstrate how long these adzes were, "obviously too big for a normal-sized human to use efficiently".
Mrs McGeady died last year. I phoned her son, Mr Stan McGeady, of Okiwi, who knew of the adzes but couldn't retrieve them from storage in time for me to photograph during my short stay.
Murray knew another Okiwi resident, who while pig hunting in Copper Mine Bay as a young man, had discovered a cave containing a full skeleton, over 7 feet (2.1 metres).
"People on the island still find collar bones, femur and so on, that are at least one-and-a-half-times the size of normal human bones. It seems clear that a race lived here long before Maori, who were killed-off by Maori."
The next day, at the Texas Cafe Claris, I met another elderly Great Barrier couple convinced that giants once existed on their island.
Alan Gray and his wife Sue have made a substantial contribution to development of Claris through quarrying, engineering, construction and land development.
Alan and Sue Gray say the giants are a fact. Photo /
Alan told me that early last century, his father farmed a drained section at the headwaters of the Kaitoke Swamp.
Yes, his dad certainly had seen a giant skeleton, found on a nearby section of Crown land reclaimed from the swamp.
"The giants are no a legend - they're an actual fact. We have no idea what happened to the bones after they were found. Dad had the impression that they were removed from the island."
So could there really have been giants on Great Barrier?
Auckland University anthropologist, Professor Simon Holdaway was skeptical.
"The pre-Maori idea is in some old text books and it resurfaces ever few years. But while reports like these make a great story, there's no basis to them. How come none of the bones have survived (to be examined).
Mr Holdaway hadn't previously heard the Great Barrier giants but it reminded him of of pre-Maori coming to New Zealand from parts of Asia and the Mediterranean.
"No evidence to back any of these claims."
And even if a large skeleton had been found it wouldn't prove the legend true, he pointed out.
"There is a range of stature in all peoples, so undoubtedly in the past taller and shorter individuals. We don't go around looking for bones to examine, but in any case, I doubt that untrained people could accurately judge stature from examining some bones they may find.
"To me this is a nice story - but all a bit make believe."
Okay then, it all seemed to be a myth, but the remote northern end of the island seemed to be a suitable place for myths.
After speaking to Mr and Mrs Gray, I spent the next night alone at Okiwi, the sole occupant of a creaking DOC house.
I kept a light on that night and, lacking a radio, sang to myself till quite late.
Paul Charman's trip to Great Barrier was sponsored by Sealink, Great Barrier Lodge and BMW New Zealand.