A video claimed to depict some sort of unknown monster or mysterious object in the Thames river has gone viral this week.

The video was posted to YouTube on March 27, shortly before April Fool’s Day. The brief and blurry video (see below) from a cameraphone shows the Thames river from a tourist cable car, and what seems to be at least two dark humps in the water before the cameraman inexplicably turns the camera away, and then back again but the humps are gone.

Loch Ness Trench Spurs Monster Speculation

Various theories have been put forward, ranging from a Russian submarine to a crude hoax to a (very) lost Loch Ness monster. So far the truth remains elusive and there are more questions than answers, beginning with the video’s source.

Who allegedly filmed this startling video? According to “The Daily Beast,” it’s a “Penn Plate,” (perhaps a pen name) who “has only uploaded two YouTube videos, both on the same day. His profile displays no photograph, no email, and no identifying information other than his username, which does not appear to match any other social media handles.

Penn has, however, licensed the video to Newsflare, an online video company that purchases rights to photos and videos, and sells them to news organizations. The videos’ original owners get a cut of the profits.”

The camerawork, as it might generously be described, also casts some doubt on the film’s authenticity. It is strange, for example, that “Penn Plate” chooses to move the camera away from the “creature” moments after it is in frame. You might expect someone who captures such a startling sight to keep the camera trained on the mysterious object as long as it’s in sight instead of panning away from the water, as he chooses to do.

The lack of other people’s reactions is also curious; judging from a bit of audio in the background he doesn’t seem to be alone, and you might expect someone else to have sighted the spectacle, or even photographed or made a video of it.

Yet not only has no one else with him come forward in the past two weeks with another photo or video, but it seems that no one even mentioned it to the press or anyone else—even to this day, the only “account” being the video itself.

Sea Monsters Real And Imagined: Photos

If what’s depicted in the video is in fact alive — and not, for example, only residing as a video effects file on a desktop somewhere — it’s unlikely to be a single enormous creature, as it appears to be in the video. Instead it’s more likely to be two smaller animals traveling together, one in front of the other but creating the illusion of one long, multi-humped serpentine form.

Researcher Loren Coleman, Director of the International Cryptozoology Museum in Portland, Maine, told Discovery News, “When investigating videos such as this one we [at the museum] start with the circumstances of who took the footage, why, when, and so forth. The answers here all appear to be innocent enough, but why the excitement? There are several mundane explanations for this one, and nothing ‘monstrous’ is needed for solving this case.

Beached ‘Sea Monster’ Just A Whale’s Head

Last year, the U.K. media reported that more than 2,000 seals and 450 porpoises and dolphins were spotted in the Thames over the last decade. This seems to be at least a pair of dolphins swimming in the gray waters of the Thames.”

Indeed, Coleman may be right: a Thames Marine Mammal Sightings Survey conducted by the Zoological Society of London collected over 1,200 sightings of marine mammals in the river over the course of a decade, the vast majority of them harbor and grey seals, which can grow quite large.

So is the video of a hoax or known animals? Either explanation seems plausible, and the video is too poor quality to decide the matter. Until and unless more information is known about the circumstances of the video (including the videographer and what others saw) the two most likely options suggest that there is no wayward river monster in the Thames.