A nerve-wracking but wonderful video has emerged of a group of curious killer whales swimming under and around a small inflatable boat full of tourists.
According to the Daily Telegraph, the videographer, who has worked on the southern California Killer Whale project since 1984, wrote online: "These wild Orcas that I have known for many years now came over to my 10-foot inflatable maybe just to say hello."
The orcas were spotted just off the coast of Los Angeles, and the footage captures them 'spyhopping' - poking their heads above water - and approaching the 10ft boat.
One passenger can be heard shouting: "We've got to go, they're under our boat!"
Rather than being scary, experts have said the tourists were 'lucky' to witness such behaviour.
According to BT News, Vassili Papastavrou, whale biologist for the International Fund for Animal Welfare (IFAW), examined the footage and said: "The people who experienced this behaviour were very lucky.
"The orcas that are spyhopping are looking into the boat. Orcas have reasonably good above water vision."
He added: "When in the company of whales, it is good general advice to allow the animals to control the nature and duration of the interaction.
"Orcas are extremely sophisticated predators. In different parts of the world they eat different species (from various fish to other marine mammals, including whales) but they are not recorded as eating people."
Naomi Rose, killer whale biologist at the Animal Welfare Institute (AWI) in Washington, told BT :"In my opinion, what this video captures is simple curiosity.
"There are a couple of populations that are known to approach divers and boats more readily, but these are the exception to the rule.
"For transients to approach a stationary, small dinghy like this in completely still water is unusual and to be honest, a bit nerve-racking.
"The dinghy is unusually small and again, that combined with the motor may have simply attracted them for some reason."