NEW DELHI -- Swami Bhakti Gaurava Narasingha paddles hard and drops into a 6-foot wave off the coast of Mangalore in South India.

As the 61-year-old surfer cuts left and races down the face of the wave spiralling toward the wastewater treatment plant up the beach, half a dozen local fishermen look on with bemused fascination at the aging white dude, who also goes by his given name of Jack Hebner.

Though India has 4,500 miles of coastline and...