New Delhi, April 6 -- When tourists travel to Seattle, it's common to take in the Space Needle and the downtown skyline from Puget Sound.

It's an itinerary that a newly arrived pod of killer whales appears to be following too.

Three orcas that had not previously been recorded in the Seattle area have delighted whale watchers with several visits just off downtown this past month. They've also cruised by other shorelines in the region.

"People . are all very happy to see this," said Hongming Zheng, who photographs whales in his spare time. It took him 10 hours of driving to find the mysterious pod. "It was epic."

Researchers keep detailed records of killer whales that frequent the Salish Sea, the waters between Washington state and Cana...