Once nearly hunted to extinction, Pacific gray whales in Mexico's Laguna San Ignacio now seem to be as curious about us as we are about them. "Here she comes again!" our guide, José Sanchez, announces as a massive gray whale approaches us for the fifth time in 45 minutes. Each time our curious new friend returns to our idle fishing boat, it stays a bit longer on the surface, watching us as we watch her.

This is our final outing to see what locals call "the friendlies" – the gray whales in Mexico's Laguna San Ignacio. As our boat quietly sits with its engine off, this 40-ton whale playfully rubs up against the sides of the boat, raising the top half of its white-speckled body and cosying up right along the hull as if to check out all six of us onboard. When the whale's eye – which is about the size of a baseball – breaks the surface and meets mine for a moment, I shriek with delight.

We're told to give whales distance, but what happens when they come to watch us? Located on the western coast of Baja California Sur's peninsula, the Laguna San Ignacio is considered the last undisturbed breeding and calving lagoon of the Pacific gray whale . The protected whale sanctuary is also home to one of the world's most unusual wildlife encounters: here, curious whales regularly, and voluntarily, seek out contact with humans. Every year from January to mid-April, thousands of gray whales arrive in the lagoon during a 19,300km journey from the icy waters of the Arctic to the warm wa.