But whereas most brushes with B.C.'s famed creatures happen from the vantage point of whale-watching boats, the Cullen's encounters are all on solid ground.
In fact, they all happen in the backyard of their home on Galiano Island which looks over Active Pass, the same route travelled by BC Ferries between Vancouver and Victoria.
"When we started seeing them it was a real bonus to having the place, that's for sure," says Gary Cullen.
And this summer, Cullen says, their encounters are especially exciting, with four baby killer whales born between last December and April of this year.
It's vital news for a population struggling to stave off extinction — they are the first babies born to the pods in over three years.
"We're all excited, because it seems like more often you hear about them dying than young ones coming into the world and surviving," says Cullen.
'It's fragile. This could end'
The southern resident orcas may be the most studied marine mammals in the world. The 81 whales swim in congested waters near big West Coast cities like Vancouver, Seattle and Victoria.
They're officially listed as endangered or at risk, in the U.S. and Canada.
The Vancouver Aquarium's Lance Barrett-Lennard, one of Canada's leading marine mammal scientists, is among those on both sides of the border keen to track the progress of the orca babies.
"So far the calves look to be in quite good condition. There's nothing I'm aware of that's a particular concern. They don't look skinny and the mothers don't look malnourished," he said during a trip on the aquarium's research vessel, the Skana, off the coast of Victoria.
"We need new whales in this population desperately, so fingers crossed that they will make it."
"The population is perilously small, there's been very few babies born and survived over the last few years and then in the last few months we've had this spate of babies born," says Barrett-Lennard.
But even though the signs are promising, there are many reasons to be cautious about calling this a turning point for the population.
It was only last December when a dead orca, J-32, washed up on Vancouver Island.
She was the fourth whale to die in the previous six months, and even more worrying, she was pregnant with a full-term calf.
Breeding-age females are crucial to the survivability of the southern resident orcas and there are just 28 left.
A necropsy determine the mother died shortly after failing to give birth to the calf.
It also concluded she was in the process of starving to death.
Barrett-Lennard says the incident left scientists feeling desperate.
"It's fragile, this could end, this entire population could wink out on us," he told CBC News.
"We're not out of the woods by any means."
Barrett-Lennard says southern resident orcas are some of nature's pickiest eaters, with chinook salmon as their main source of food, a species that's fallen dramatically in recent years.
"In a good salmon year, there is plenty to eat, but in a bad year, they are on the edge," says Barrett-Lennard.
"So we think part of the reason the reproduction rate is so low is food supply."
'A wonderful sign of hope'
For whale watchers both here and in the U.S., the orca babies are the first positive news in a long time.
Killer whales are a big business — with 400,000 tourists taking whale watching trips in B.C. and Washington state in 2014.
CBC News recently spent a day with the crew of the Chilkat Express, a high-speed catamaran passenger ferry based in Edmonds, just north of Seattle.
Along for the ride was Michael Harris, executive director of Pacific Whale Watch Association, which represents 32 operators in B.C. and Washington.
"When these animals got listed on the Endangered Species Act and Species at Risk, many people thought they were on an irreversible slide to extinction," says Harris.
The trip on this day took visitors a few kilometres offshore from Victoria, where the crew struck whale-watching gold.
One of the babies, known as J-50, was playfully jumping out of the water about 200 metres away.
"The opportunity to come out here and be with one, just one, is awesome, just absolutely awesome," says Shelley Thiessen, a tourist visiting from Kamloops.
"It just gives you a warm, fuzzy feeling."
The young whale looked healthy, at least from a distance.
"Can you imagine this area without southern resident orcas?" asks Michael Harris.
"So this is a boost of hope. It's a wonderful sign of hope."
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