Maxime Veilleux and Matteo Endrizzi were finishing their sunset dive off Nanoose Bay on Sunday and heading to the shore when something unusual caught their eyes.
A harbour seal was hanging vertically in about three metres of water trying to get at something in a rock crevice.
In turned out to be the seal’s intended supper, a giant Pacific octopus, and the battle that ensued — which was caught on film — was a rare sight, said Veilleux.
“To my knowledge, this is the first time this has been captured on camera,” said Veilleux, a marine biologist based in Nanaimo who has been scuba diving for 16 years.
“People see sea lions on the surface eating octopus, but you never see it underwater.”
Veilleux said seals are normally very skittish and octopuses are usually only active in the evening, which is why many divers in the area choose to use lights while diving in the early evenings.
The seal was biting into one of the octopus’s arms to try and pull it from a den, but when the seal went up for air, the octopus made a break for it.
It measured about two metres long as it whizzed by the divers, and discharged ink to confuse the seal as it dove back down in pursuit.
The octopus took cover in rocks, but the seal grabbed one of the octopus’s arms and twisted and turned until it ripped off.
“I felt really bad for this octopus but I don’t think humans should interfere with nature,” said Veilleux.
She said the octopus swam off with seven of its eight arms and the seal returned to the surface to eat.
The whole ordeal lasted about two minutes and Veilleux and Endrizzi posted their video to YouTube on Monday.
Veilleux identified the octopus as male, noting one of the eight arms is actually the animal’s penis — which was intact as it disappeared into the depths.
She said octopus are capable of regenerating lost appendages.
Veilleux said evening dives are often the best times for seeing unusual creatures like octopus.
The diving buddies have filmed ruby octopus — a much smaller version about the size of a human hand — various types of squid and crabs and the elusive Pacific spiny lumpsucker, a golf-ball-shaped fish and “trophy for divers.”
Nanoose Bay just north of Nanaimo is considered one of the best diving sites on Vancouver Island, where divers can see wolf eels, Puget Sound King crabs, brittle and feather stars, boot sponges, nudibranchs and swimming scallops.