There, fishermen were casting wide swathes of krill into the water. Suddenly a greyish-black snout broke the surface, huge mouth agape. Tourists from the nearest boat rapidly jumped into the water and began splashing about - most bobbing around in orange life vests. A succession of canoes converged on the area and then suddenly I was in the water too.

Wearing just a mask and snorkel, I dove down and saw two giant beasts circling below me. It was awesome. Not surfer awesome, but more in the original sense of the word - that which installs awe. As they rose to the surface to catch another mouthful of krill, their size became clear - no more than 3 meters from me. People darted in and out - hands outreached to touch the animals, legs extended for just that one point of contact. It was an underwater mob scene and I returned to the boat.

As the canoe gently rocked, I listened to the laughing and screaming and watched the frenzy in the water. It was a one-of-a-kind experience that I will remember for the rest of my life - watching those gentle creatures glide below me. And my brain knew that they were bringing the village out of poverty, that their kind had been hunted and killed by these same fishermen just a few years before as nuisances that drove away fish and destroyed their nets. But my heart was weary and I felt dirty. It was time to leave.