Conall Melarkey said he and friend David Lynch were filming their project at Lough Foyle, which separates the Irish province of Ulster and County Londonderry in Northern Ireland, when a large creature broke through the surface of the water, The Scotsman reported Thursday.
"Looks like we have our own Loch Ness Monster -- any experts out there?" Melarkey said in posting the clip to YouTube.
YouTube comments suggest the object could be a whale, sea debris or an intentional hoax, a possibility Melarkey denied.
"Can't believe people are suggesting this is just a viral promotion for our college project which is only two minutes long," he said.
The modern myth of the Loch Ness monster started 80 years ago, with a headline in the Inverness Courier reading, "Strange spectacle on Loch Ness," detailing the accounts of a couple who claimed to have seen a large creature swimming in the loch, The Guardian reported.