If we were to ask you to name the possibly real water monster with humps, you’d surely say the Loch Ness Monster. But by the time this interview is over, your answer should be the Gloucester Sea Serpent. Our local monster is arguably even older and more widely witnessed than Nessie.

For a deep dive into the Gloucester Sea Serpent, there’s no better guide than local folklore expert and host of the “New England Legends” podcast Jeff Belanger. He joined GBH’s All Things Considered host Arun Rath to discuss this chapter of cryptozoology. What follows is a lightly edited transcript.

Arun Rath: Let’s talk about the Gloucester Sea Serpent because I know about this — again — thanks to you. This actually goes way back. When was the Gloucester Sea Serpent first sighted?

Jeff Belanger: The first documented sighting that I found goes all the way back to 1638 when John Josselyn wrote a book called “An Account of Two Voyages to New England,” where he described a sea serpent or snake that lay coiled up like a cable upon a rock at Cape Ann. He was told, “Yeah, that’s not something we mess with. It’s just known.”

Centuries later, the sightings would get so frequent — especially in August of 1817, there were so many sightings, allegedly, it was seen every single day during that month on Gloucester and Cape Ann. People would set out lawn chairs, fishing vessels spotted it — one crewman even took a shot at it with his rifle.

Rath: It’s amazing to imagine that we think about these sorts of sightings as fleeting things, but it was so regular that it stopped being worth mentioning.

Belanger: It was so regular. At one point, the Boston Globe posted an article saying, “We’re not going to cover the sea serpent anymore. The fact that it exists is a foregone conclusion.” They were sort of tired of covering it and said, “We’re going to stop.”

By the way, this thing has been described as up to 100 feet in length and a body as wide as a barrel. This was reported again and again over the span of many, many years.

Rath: Give us a bit more of the physical descriptions. [Is it] sort of like a giant sea serpent?

Belanger: Basically, a giant snake. A serpent snake, right? That’s it.

You know, “monster” would be used, but it didn’t behave or look anything different than a snake, although they claimed it had — almost like — a horse’s head. It would rear up out of the water, and it would move in a caterpillar motion, as it was described, over the water.

A long anatomical drawing on aged paper shows a long scaly serpent with a slightly ridged spine.
A depiction of a sea serpent, drawn more than two centuries ago in 1817.

Rath: With people putting out lawn chairs to watch it, clearly, people were seeing something. What are some of the theories about what they might have seen, if it weren’t its own unique entity?

Belanger: What’s interesting to me is that the story is identical to Cassie the Sea Serpent in Casco Bay, Maine, which isn’t that far away. Those sightings go back to 1779. Same thing: Giant snake, 100 feet long. They’re even similar to some freshwater sightings, like in Lake Memphremagog from northern Vermont and also Champ, of Lake Champlain. But those are, of course, freshwater bodies of water.

On the one hand, it begs the question: Is there some giant creature out there that we don’t know about that we haven’t cataloged yet? Or is everybody sort of making up the same story? Or are they confused by something?

But at the same time — I don’t know how much time you’ve spent in Gloucester; I mean, I’ve been there a fair amount — I’m not going to argue with Gloucester fishermen when they say they’ve seen something in the water, you know? That’s their business.

Rath: With Gloucester — I know Inverness and the towns around Loch Ness do a pretty good job marketing Nessie. Does Gloucester work to keep the legend alive?

Belanger: I’ve not seen anything in Gloucester, as far as keeping the legend alive. Now, if you go to Lake Champlain — oh my goodness, right? I mean, there’s a triple-A baseball team called “The Vermont Lake Monsters.” There are T-shirts you can buy. There are plaques and statues all around the lake. There are sightings. But I’ve never seen Gloucester trying to cash it on it. Maybe there’s a missed opportunity there, Arun.

Rath: Sounds like it. I mean, I imagine it’s super nice in the summer. It’d be a great thing to make a Sea Serpent Festival.

Belanger: Well, the other thing is that the last sighting was a long time ago. I mean, allegedly, in 1965, there was a sighting — we’re not totally sure, maybe someone was mistaken.

But the theory is that, if this is a giant sea snake or some creature that we don’t really know about yet, the waters probably got overfished, and it just moved on to where there’s more abundant food. An animal that large would require a lot of calories, so it would have moved on to a place where there’s more food.

Rath: Interesting. It also sort of scans what we know about fish and wildlife in the area compared to that time.

Belanger: Right, exactly. There was an article in the Skeptical Inquirer that came out a few years ago by Joe Nickell that basically said, “The mystery is solved. It’s a narwhal.”

I know Joe. Joe was born and raised in Kentucky and got his PhD from the University of Kentucky. He’s what I imagine a Gloucester man would call a “landlubber.”

But a narwhal is basically an animal we’ve known about since the mid-1500s. It reaches about 14 feet in length. It looks almost like a porpoise without a dorsal fin, and it’s got a horn — or, almost like a spear sticking out of the top of its head.

I don’t imagine anyone would confuse that for a giant snake, but, certainly, if you had never seen one, I imagine the head with the spear could look different to you.

But I don’t think you’d confuse 14 feet with 100.

Rath: You mentioned some other sea creatures — sea serpents — in the Northeast, but there was one other one I wanted to ask you about, if we have the time, because the description is unlike any of the others. Can you tell us about the Herring Cove Sea Serpent?

Belanger: Yeah. So, the Herring Cove Sea Serpent dates back to 1886, and this is a wild one. Herring Cove, right near Provincetown at the tip of Cape Cod in Massachusetts.

This creature was described as being about 300 feet long, 20 feet in diameter and had six eyes on sprouts.

To me, this sounds like a tall tale. I can buy into the fact that maybe there are snakes growing larger than we think in the ocean, but an animal like this I’ve never heard described anywhere — before or since. But it’s unique to Herring Cove.

Rath: It’s kind of almost psychedelic-sounding, which makes you think that they have multicolored scales or something.

Belanger: Whenever we see something that doesn’t compute, we try so hard to put a label on it because it just gives us a sense of control, even if it’s a false sense of control.

We say, “Okay, this is just a snake that’s large. This is a creature we don’t know about yet. There’s nothing supernatural or paranormal about it, it’s just literally a flesh-and-blood animal.”

But at the same time, we’ve learned again and again: We don’t know every creature that walks the Earth with us, especially when it comes to the ocean.