"Because of their isolation, they have become their own distinct population," Hartford told KHON2. She also told the news outlet that the pair seen in the video are a mother and her calf, and that they were encountered at a depth of about 1,500 feet.
The Specialty Tours Youtube page notes that while these creatures share a few things in common with the better known killer whale, or Orca -- similar skulls, lifespan, and breeding patterns -- the two are yet very different.
For instance, false killer whales, the tour groups says, will rarely attack mammals.
The Hawaiian false killer whales, such as those seen here, are considered endangered, with only an estimated 150 of them living amid the islands.
Of course, it's the "smile" early in the video that's really grabbing people. Perhaps the animals were warming up to the visitors in their waters.
via KHON2. Hat tip Underwater Times.