VICTORIA -- A group of divers were greeted with a welcome surprise after a small cluster of orcas swam near their vessel off Vancouver Island on Monday.

Victoria's Five Star Whale Watching says it was operating a dive charter near Beecher Bay, in south Vancouver Island, around 11:30 a.m. when the whales were seen.

Jasspreet Sahib, a marine naturalist with Five Star, says the visit came as "quite a surprise" since the group was out for diving, not whale watching.

"They essentially encountered us," she said.

The orcas were Bigg's killer whales and are believed to belong to the TO86A and T109A2 families.

The encounter was particularly exciting because it was the first time a new calf was spotted. Sahib says there was a lot of orange colouration on the young killer whale, "indicating that it was a brand-new calf."

The company says researchers are still looking into who the calf's mother is.

Sahib says Bigg's killer whales are common to the area and regularly swim there from other regions of B.C.'s coast. There's ample prey available in the Beecher Bay area for the orcas, such as seals and Steller sea lions.

Bigg's killer whales, also known as transient killer whales, are different than southern resident killer whales, which are critically endangered.

Late last year, however, researchers celebrated the birth of a new southern resident killer whale calf, which was confirmed to be a female last week.

Researchers say it's important for females of the species to be born to help increase the population.