Ben Laurie, 21, encountered the bizarre creature while diving near Cape Brett on New Zealand’s North Island.
He filmed the moment he came across the strange-looking animal.
In the clip, Ben is seen approaching the long cylindrical creature.
It stretches for several metres, with fish swimming near it.
“It did look almost like a big condom”
Ben Laurie, diver
“We were diving there for kingfish and we had plugged a couple and then we were coming up from one of the dives when my friend saw this thing,” said Ben.
“It did look almost like a big condom.
“It was 10 metres long and almost half a metre wide, and it was just flowing with the tide.”
Ben, who has years of experience in the water and is an ambassador for the WildBlue dive shop, said he had seen nothing like it.
“I didn’t know what it was at the time, so it was quite a confusing thing,” he said.
“We get these little like plankton build-ups – they’re like small stringy things but they’re only like 20cm long – so I thought it was just a large one of them.
“But one of the guys touched it and said it wasn’t soft at all, it was more like a cardboard sort of texture.”
The creature is believed to be a pyrosome – a floating colony which consists of billions of tiny sea squirts moving together.
It feeds by filtering microscopic plant cells out of the sea, with each squirt drawing in water from outside the pyrosome and then releasing the filtered water inside the colony.
Ben, from Kerikeri, New Zealand, said it was quite rare for the creature to be swimming in the shallows, given it usually stays at depths of 2,000 metres.
He suggested the pyrosome could have been “sick”.
“Once it gets a bit too high, because it’s got more of a softer texture, the fish seem to eat it, so that’s why it stays deep,” the diver added.
“A scientist said it’s pretty much a once-in-a-lifetime rare thing to see.”