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The amazing Hook Island sea monster photos, revisited

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Robert Le Serrec's Hook Island sea monster, supposedly photographed December 12th 1964.

Long-time readers of Tet Zoo might remember Sea Monster Week: a series of articles I ran at Tet Zoo ver 2 back in 2008. 2008? That’s, like, years ago. A recent discussion with ZSL’s Sam Turvey got me thinking about the Hook Island sea monster – an alleged sea monster photographed during the 1960s and frequently featured in books on monsters and mysteries. And I have sea monsters on the mind a lot anyway, due to the recent release of the Kindle version of Cryptozoologicon Vol I and the impending release (December 6th) of the hard-copy version (we’re holding a launch event in London: details here). Inspired, I’ve decided to republish my article on the Hook Island case, with updates…

The best known of the Hook Island sea monster photos is familiar to many (the two or three others are less familiar: read on). As shown above, it features a gigantic, tadpole-like monster, supposedly encountered in Stonehaven Bay, Hook Island, Queensland, by Robert Le Serrec and his family and a friend during the December of 1964. Judging from comments I’ve seen online, people nowadays tend to assume that it’s a photoshop job. In fact, it’s a classic, much-reproduced image, widely discussed in the cryptozoological literature.

Excellent cartoon rendering of the Hook Island monster (imagined as a gigantic axolotl-type creature) by eternalsaturn.

Let’s note to begin with that – if the object depicted here really is a large, unknown marine animal – then it perhaps shouldn’t be featured on a website called Tetrapod Zoology, since the most popular proposed identification of the creature is that it’s some sort of weird giant fish. We’ll come to the subject of identification in a minute. The story starts in March 1965 when Breton photographer Robert Le Serrec claimed, in Australia’s Everyone magazine, that he had obtained excellent, genuine photos of a real sea serpent: a creature discovered by chance while it resting in a lagoon. A very detailed account of the case was written up by Heuvelmans (1968) and what I’ve written here is mostly based on that account. Shuker (1991) and Newton (2005) provided further information. [Adjacent image by eternalsaturn.]

Wrecked on the Great Barrier Reef with his family and Australian friend Henk de Jong, Le Serrec and family had bought a motor boat and had decided to spend three months on Hook Island (one of the Whitsunday Islands). They were all crossing Stonehaven Bay on December 12th 1964, when Le Serrec’s wife spotted a strange object on the lagoon floor. It proved to be a gigantic tadpole-like creature, estimated to be about 30 ft long. They took several still photos, gradually moving closer. Eventually, Le Serrec and de Jong plucked up the courage to approach it underwater in order to film it. It proved larger than first thought, with its estimated length now increasing to 75-80 ft. It didn’t move and they suspected it might be dead, but just as Le Serrec began the filming it opened its mouth and made movements toward them. They returned to the boat and, by the time they got there, the creature had moved off.

This version of the image is findable online. I don't know if it's really one of Le Serrec's originals, or a recreation made far more recently. Would love to know. UPDATE: see comments 1 and 2 below.

A large pale region interpreted as a wound was visible on the right side of the tail, and it was suggested that this (perhaps – they speculated – caused by a ship’s propeller) had caused the animal to take rest and refuge in the shallow bay. The eyes, located on the top of the head and well away from the front of the snout, were pale and possessed slit-shaped pupils. Mostly black in colour, the animal had brown transverse stripes and its skin was smooth in texture. It possessed no fins nor spines of any kind and they didn’t see teeth inside the white mouth.

Heuvelmans (1968) reported that he had done some checking on Le Serrec and found that “he had left unpaid creditors in France and did not seem very trustworthy” (p. 533). Coleman & Huyghe (2003) stated that he was wanted by Interpol. Character assassination of this sort is argued to be irrelevant by some, and maybe it is. On the other hand, there are good reasons for thinking that people with a track record of being untrustworthy really are untrustworthy. Ivan Sanderson had been contacted about the story in February 1965 (Le Serrec had initially approached the American media in order to get the best price for the images) and had concluded that the object might be either a plastic bag used by the US Navy “for experiments in towing petrol”, a deflated skyhook balloon which had become covered in weed, or a roll of cloth which had been tied together in places (Heuvelmans 1968). These are weirdly specific suggestions and don’t seem like the most sensible possibilities to me: what about the more obvious idea that (if not a real animal) it was a custom-shaped expanse of plastic sheeting, weighted down with sand?

The swamp eel Synbranchus marmoratus, as illustrated by Paul Louis Oudart in 1847 (image in public domain). Not in the least bit tadpole-like.

Sanderson later suggested that the creature might be a giant synbranchid, or swamp eel*. Synbranchids are long-bodied acanthomorph teleosts, mostly of freshwater and estuarine habitats, well known for their ability to breathe air and undertake terrestrial excursions. However, they’re small (generally less than 60 cm long) and are eel-shaped, not tadpole-shaped, so this doesn’t look like a sensible idea either. Pressed to propose a ‘real animal identity’ for the creature, Heuvelmans noted in a magazine article that it could be “some kind of gigantic eel-like selachian”, which would be a huge deal if correct.

* I haven’t seen Sanderson’s article – published in True Magazine – and am going from Shuker (1991).

Skull of the giant Triassic mastodonsauroid temnospondyl Mastodonsaurus. Photo by Darren Naish, CC BY.

However, Heuvelmans (1968) actually favoured the idea of plastic sheeting weighed down with sand. He noted that the position of the eyes was highly suspicious given that most vertebrates either have their eyes on the sides of the head, or nearer the snout. Arguments like that don’t really count for much though, as unknown animals are allowed to have their eyes wherever they like, and – anyway – there are vertebrates that do have eyes positioned similarly to those of the Hook Island monster (like mastodonsauroid temnospondyls… yeah, maybe it’s a late-surviving, limbless mastodonsauroid).

The last time I published this article (2008), some aggressive commenters claimed with misplaced confidence that the ‘creature’ might actually be a tightly bunched shoal of fish. I think that this idea is an immediate non-starter, for three main reasons. (1) The edges of even the most tightly bunched fish shoal are ‘messy’, lacking the straight, obvious edges seen on the Hook Island monster. (2) The shoals don’t become organised into something as neat-looking as the Hook Island ‘monster’: the ‘monster’ has an obvious fat head/body and long, gently tapering tail, while even the most tightly packed, monster-shaped fish shoal is far more amorphous in form. (3) Fish shoals are dynamic and constantly changing shape and position, whereas Le Serrec’s photos show that the object was pretty much stationary while he was taking the photos.

There are other photos

While the still photo shown at the very top of this article has been reproduced a lot, some other images haven’t been. One (shown here on the left) shows the creature at closer range, and from a different angle. Another (shown here on the right) shows the head as seen directly from the front, at much closer range. It shows clearly that the white eyes you can see on the top of the head really are meant to be the eyes, but its wavy, broken outline provides further support for the idea that the creature is hoaxed, as the wavy outline shows clearly that the edge of the ‘creature’ is partly overlapped by sand. Ok, you might say that the creature had partially buried itself in the sand, and indeed Le Serrec reported that this was indeed the case. But in at least four spots it looks like someone has placed handfuls of sand on top of the edge of the creature: exactly what you would do if trying to weight down a monster-shaped sheet of plastic.

The final piece of evidence demonstrating that the whole episode was a hoax comes from the fact that, in 1959, Le Serrec had tried to get a group together on an expedition that would prove “financially fruitful”, and that he had “another thing in reserve which will bring in a lot of money… it’s to do with the sea-serpent” (Heuvelmans 1968, p. 534). Incidentally, the film supposedly taken of the creature revealed nothing.

Did Le Serrec inspire Heuvelmans, or did Heuvelmans inspire Le Serrec?

A rendition of Heuvelmans's 'yellow belly', by Darren Naish.

One last thing: when most people think of sea serpents, they generally imagine immense, snake-like creatures. Where did Le Serrec get the idea of a giant tadpole monster from? As a kid, I always thought that Le Serrec was inspired by ‘yellow belly’, a marine cryptid hypothesised to exist by Heuvelmans (1968) and described as shaped like a tadpole, 60-100 ft long, marked with black transverse bands on its sides, and restricted to the tropical waters of the Indian and Pacific oceans [my own, c. 1988, effort to reconstruct yellow belly shown in adjacent image]. Given that Heuvelmans first published his ideas on ‘yellow belly’ in 1965 (when the French-language precursor of In the Wake of the Sea-SerpentsLe Grand Serpent-de-Mer, appeared), while Le Serrec took the photos in December 1964, this can’t be possible – can it?

I wonder if Heuvelmans had published a description of ‘yellow belly’ prior to 1965, and that this description had been used by Le Serrec in making the hoax. So far as I can tell, however, Heuvelmans did no such thing. But could Le Serrec have seen Le Grand Serpent-de-Mer in early 1965, and just lied about the date of the encounter? That would require some detailed investigation (you’d have to show, for example, that Le Grand Serpent-de-Mer was available prior to March 1965, and that Le Serrec had gotten hold of a copy). What about the opposite idea: that Heuvelmans had been inspired by the Hook Island creature when coming up with the idea of ‘yellow belly’? This would assume that Heuvelmans had initially regarded the Hook Island creature as genuine, and there’s no indication of that (it’s not impossible, however). Furthermore, Heuvelmans seems to have based ‘yellow belly’ on several other, clearly identified cases (dubious and ambiguous cases (see Magin 1996), but clearly identified nonetheless).

It was reported in 2003 that Le Serrec has been found alive and well and living in Asia, and there were apparently plans to interview him about the case. That might be interesting but, regardless, the Hook Island case is undoubtedly a hoax, albeit a pretty good one I think.

Many of you who grew up in the UK will appreciate the relevance of this book cover in connection with this story. Note the depictions of Frame 352 and the Loch Ness Muppet. Cover painting by Tony Blythe.

For previous Tet Zoo articles on sea monsters, see…

Refs –

Coleman, L. & Huyghe, P. 2003. The Field Guide to Lake Monsters, Sea Serpents, and Other Mystery Denizens of the Deep. Tarcher/Penguin, New York.

Heuvelmans, B 1968. In the Wake of the Sea-Serpents. Hill and Wang, New York.

Magin, U. 1996. St George without a dragon: Bernard Heuvelmans and the sea serpent. In Moore, S. (ed) Fortean Studies Volume 3. John Brown Publishing (London), pp. 223-234.

Newton, M. 2005. Encyclopedia of Cryptozoology. McFarland & Company, Jefferson (N. Carolina) and London.

Shuker, K. P. N. 1991. Extraordinary Animals Worldwide. Robert Hale, London.

Darren Naish About the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at! Follow on Twitter @TetZoo.

The views expressed are those of the author and are not necessarily those of Scientific American.

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Comments 36 Comments

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  1. 1. Reliant Robin 10:04 am 11/23/2013

    Great to see this article revisited, it’s an old fave in my bookmarks.

    Re the image with the boat in the background – there’s a drawn copy of a very similar picture in Tim Dinsdale’s The Leviathans, though it’s slightly cropped and compressed to fit it on the page. Dinsdale copied a lot of photos in The Leviathans, presumably for copyright reasons. The drawing is labelled “based on Robert Le Serrec’s photo” so presumably this is the actual original photo. I don’t think I’ve seen it published before though.

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  2. 2. naishd 10:13 am 11/23/2013

    Huh – you’re right, I had completely forgotten this (Dinsdale’s drawing). So, it is one of Le Serrec’s originals after all. Thanks.


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  3. 3. llewelly 10:26 am 11/23/2013

    I find it strange and fascinating that such mediocre hoaxes sometimes have such long lifespans in the cryptid literature.

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  4. 4. Tuinlaaf 1:57 pm 11/23/2013

    Massively off-topic, but I just wanted to say how much I enjoy this blog. I’m a complete amateur, unlike many of the commenters. I’m just a simple reporter who didn’t finish his education, BUT…I AM one of those people who can get really excited by phylogeny and cladograms. Oh, AND cryptozoology of course.

    Anyway, keep up the good work!

    Oh, i’d like to see some in-depth coverage of artiodactyl phylogeny :) are you planning something like that? (probably not ;) )

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  5. 5. Andreas Johansson 2:53 pm 11/23/2013

    yeah, maybe it’s a late-surviving, limbless mastodonsauroid

    Nah, too obscure. Cryptic survivors are always well-known critters. More likely it’s a late-surviving aquatic limbless shortnecked sauropod.

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  6. 6. Heteromeles 4:28 pm 11/23/2013

    It’s not one of godzilla’s sperm?

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  7. 7. naishd 5:02 pm 11/23/2013

    … last time round, a hilarious joker said King Kong’s sperm :)

    Tuinlaaf: thanks loads, thanks for commenting. Artiodactyls: sure, one day…


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  8. 8. GreatAnarch 6:00 pm 11/23/2013

    The ‘US Navy experiments in towing petrol’ were real enough. This probably refers to the Dracone barge, a large tube full of liquid towed behind a ship. They were invented in 1956 and can be as much as 300 ft long. (They were supposed to have been inspired by Frank Herberts ‘The Dragon in the Sea’, hence the name). The ‘eyes’ might be attachment points for towing.

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  9. 9. naishd 6:28 pm 11/23/2013

    Oh yes, I know about these flexible petrol tank things.. the reason it’s such a weird suggestion is that they are (and were) tubular, not tadpole-shaped. I actually think that Sanderson was really bad at coming up with sensible suggestions – he tended to go for the bizarre and extravagant.


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  10. 10. AlHazen 1:20 am 11/24/2013

    Since some people have said that various sea (and lake) serpenty cryptids are late surviving Basilosaurids, sea serpents to Artiodactyl phylogeny isn’t all that great a leap!

    There’s a white spot that might be (meant to be) the monster’s right eye visible in the familiar photo reproduced at the top, but it looks strangely placed: the very similar photo reproduced further down — the left-hand photo of the pair of “head” photos after the “There are other photos” heading — seems to have it in a more plausible position. If it’s a real beastie, this will have to be … I don’t know, maybe weird refraction phenomenon caused by irregular wave form or something. If it’s a hoax, maybe one of the eyes had its position corrected between shots (or slipped between shots if the top photo was the first).

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  11. 11. Cameron McCormick 9:20 am 11/24/2013

    Coleman & Huyghe (2003) stated that he was wanted by Interpol
    Heuvelmans (1968, p. 534) states this was because he left France without paying for supplies and also apparently charged people he never brought along.

    “some kind of gigantic eel-like selachian”
    Enigmatically, Heuvelmans suggests some of the “Super–eels” may be serpentiform rays or guitar–fish! This would seem like a better suggestion for the Yellow–belly…

    I actually think that Sanderson was really bad at coming up with sensible suggestion
    I’m shocked he didn’t say they were bags filled with chickens being transported to film studios.

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  12. 12. hazmaq 11:20 am 11/24/2013

    I have a birds eye view of a very calm 4′ deep piece of river 25 yards from my house. Not a beaver, otter or large fish can pass without leaving a surface disturbance of some kind. This huge creature seems not to have any effect on the ripples seen in this photo.

    This may also be once nice catch now caught up in a pc of debris toting fishing line..

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  13. 13. Heteromeles 11:27 am 11/24/2013

    Amusing that a Google image search for Dracone barge pictures turns up this blog page. Google likes you, Darren.

    Anyway, the body of the creature could be something like a small dracone barge or similar tube. It would be somewhat easier to lay out a partially filled tube on the sand than a strip of plastic. If the body was a flat sheet of plastic, laying out that body curve would have been harder, because the plastic would tend to fold and get moved around by currents and such. flexible tubes can handle such a curve, at least according to the Google images. In this conception, the head is a different piece, probably laid out over a pile of sand, with sand or lumps of limestone (or dead coral) for the eyes. I’m not sure whether they fixed the eye position between pictures, or whether the head is simply a black tarp over an irregular heap of sand, and the three-dimensionality of the pile makes the eye position look weird between pictures.

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  14. 14. naishd 4:09 pm 11/24/2013

    Heteromeles: good call.


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  15. 15. ekocak 9:37 am 11/25/2013

    Can I just say I love the cartoon illustration for the article? Something about that interpretation really speaks to me…

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  16. 16. Yodelling Cyclist 7:15 pm 11/25/2013

    I appreciate this is off topic, but I would like to congratulate Darren on not using the phrase “bat shit crazy” in public response to certain recent technical questions.

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  17. 17. naishd 4:09 am 11/26/2013

    Ha :) Yod: I can’t possibly imagine what you’re referring to. We’ll keep it secret.


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  18. 18. Jerzy v. 3.0. 8:58 am 11/26/2013

    BTW it is possible to develop a software to smoothen an image of an underwater object distorted by waves.

    However it is much less possible, that the “monster” will be anything interesting.

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  19. 19. John Harshman 11:36 am 11/26/2013

    …the reason it’s such a weird suggestion is that they are (and were) tubular, not tadpole-shaped.

    The photos could be of a tubular object, if the “head” is merely higher up and closer to us, while the “tail” is a tube of the same shape but mostly buried in sand.

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  20. 20. Yodelling Cyclist 7:36 pm 11/28/2013

    Well, if we need more comments, does anybody want to comment on the more plausible sea monster sightings? The Daedalus and Valhalla sightings, for example, or maybe the Sea Ape?

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  21. 21. BrianL 4:56 am 11/29/2013

    The Sea Ape is certainly a very interesting cryptid, mostly because of the credentials of Steller. I have to admit that Steller’s credibility and him apparently observing the creature for hours on end are the main reason why I don’t simply dismiss the Sea Ape as a hoax or a misidentification. The main problem is that it simply doesn’t resemble any known creature, prehistoric or otherwise. (At least not to me.) While I have a problem with Steller supposedly not being able to identify a seal (mutant, mutilated or otherwise), it’s very hard to come up with another plausible identity for this creature.

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  22. 22. naishd 5:17 am 11/29/2013

    Oh man, the sea ape — I could do a whole article on this beast (and, indeed, it’s featured in Cryptozoologicon Vol II). Most of what you’ve read about this animal is nonsense – it was not at all ‘ape-like’ or primate-like, but was apparently so named because it was agile and seemingly playful. The suggestion has been made that it could simply have been a pinniped, or even that Steller was making a joke at the expense of a fellow crew member. However, a ‘Simia marina’ of the sort that Steller said he saw was already known to the naturalists of the 1700s: the name was apparently used for chimaeras (or ratfishes or rabbitfishes). These can swim rapidly with a flying motion of their large pectoral fins. So, ‘sea ape’: nondescript pinniped, outright hoax, or chimaera? We’re kidding ourselves if we think that we can ever know for sure.


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  23. 23. Yodelling Cyclist 6:13 am 11/29/2013

    Still leaves the joys of Daedalus and Valhalla.

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  24. 24. Yodelling Cyclist 6:14 am 11/29/2013

    I’ve never written a sentence that looked more like a Cold War recognition code…

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  25. 25. naishd 7:08 am 11/29/2013

    Daedalus: Lt Drummond’s drawing makes the object look lame and boring, nothing like the spectacular blunt-headed, maned sea serpent of the famous ILN piece. Could have been just about anything, alas.

    The Valhalla incident: I still think this one has to rank as a possible unknown creature. Really hard to think what sort of known creature could possess the features it supposedly combined (big, ray-finned dorsal fin and long neck). Plus (unlike many sea monster witnesses) Maede-Waldo and Nicoll were pretty credentialed, and with published work showing that their observations should be taken as reasonably accurate.


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  26. 26. Yodelling Cyclist 7:32 am 11/29/2013

    The only flimsy excuse for the Valhalla creature is that, being close to Brazil, a mass of vegetation, somewhat decomposed and wrapped in weed, generated the apparent fin shape (maybe a tree root system, with the body of the tree hanging in the water for some reason to do with its decomposition), and a large anaconda raising its head in front. The mass of the tree could, conceivably, act as a drogue sail and by this method the mass may have been propelled by a sub-surface current. It’s flimsy, and requires that certain observations were errors (the eye’s position relative to the mouth, the precise shape of the head).

    Or maybe this is the first observation of a trans-Atlantic dispersal of Mokele-mbembe.

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  27. 27. Heteromeles 12:01 pm 11/29/2013

    I don’t know about trees, but I do wonder about distances in the Valhalla encounter–I’ve misestimated them myself, many times. How did they get the scale on the monster they saw? Could it have been smaller and closer?

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  28. 28. Heteromeles 12:06 pm 11/29/2013

    @John Harshman: If the Hook Island monster is a tube with one end floating towards the surface, we’d expect that a) the parts deeper in the water would be more blurry, due to distortion from the water, and b) that there would be a smooth increase in diameter at the part which was bending upwards. This doesn’t appear to be the case with the head in either photo. I’d suggest that the thing is therefore tadpole shaped, although that’s really because we’re all shying away from speculating on Le Serrec’s motives in creating a giant spermozoic sea monster.

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  29. 29. ekocak 1:22 pm 11/29/2013

    What about Richard Ellis’s theory that the Valhalla monster was the top portion of a giant squid with one of the tentacles sticking weirdly up out of the water? :)

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  30. 30. John Harshman 7:24 pm 11/29/2013

    Heteromeles: I’m not suggesting the scenario you think. I’m suggesting a tube that’s mostly buried in sand, except for the front end. The photos aren’t good enough to convince me that isn’t the case. Or that it is. But I see no strong evidence for a tadpole shape.

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  31. 31. Heteromeles 10:24 pm 11/29/2013

    Now I understand. It’s possible, although I’d suggest that if so, it’s possible it’s not fully inflated. That would make it easier to bury, by flattening it and burying the flat edges.

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  32. 32. Cameron McCormick 3:35 pm 11/30/2013

    RE: The Valhalla sea serpent; after seeing a thermoregulating Sea Lion, it’s hard to imagine the encounter being with anything other than an otariid. The most likely candidate would be Arctocephalus tropicalis which has been observed off Sergipe (~10° S), around the same latitude as the encounter (7° 19′ S), and has a fairly conspicuous light neck.

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  33. 33. Heteromeles 8:37 pm 11/30/2013

    Somewhat off topic, but since we went with Valhalla, I think some might like this link:

    Link to this
  34. 34. Jerzy v. 3.0. 6:33 am 12/2/2013

    Anybody can find a picture of an emaciated sealion?

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  35. 35. Heteromeles 6:56 pm 12/9/2013

    Most pictures of emaciated sealions are starving pups. However, there’s a picture of a waving sealion at Here’s a waving seal, just for fun:

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  36. 36. Ford Landau 9:08 pm 12/17/2013

    Wow, this is one of the best online discussions I’ve read in a long time! I have always been amazed by the picture of this “monster” after seeing a large color picture of it in a book on sea monsters as a kid back in the 1970s. I know many pictures of sea monsters are floating logs or outright fakes, but I always held out the hope that somehow this one was genuine. It just looked so good, and the picture looked exactly like what I’d expect a submerged sea monster to look like, so it seemed even more difficult to dismiss than the iconic Nessie in the “surgeon’s photo” (an admitted fake) or the full color one of Champy that turned out to be a toy dinosaur in the water. After reading this great article and taking a new look at the pics, as well as the discussion (especially Heteromeles mention of the “monster” possibly being a “flexible tube” with the head being a separate piece), I have to admit after a few decades of hoping otherwise that this is in all likelihood yet another hoax. Taking a good look seems to indicate that it is either a tube or it is something weighted down with the surrounding sand.
    Well, in my opinion the guy who pulled this off sure did a good job, I don’t think it’s a mediocre hoax at all. I still think large unidentified sea creatures exist but this probably isn’t one of them. Thanks for a great article and very interesting discussion.

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