STREAMING NOW Snorkel in a freshwater river for a brief encounter with an eel, a lamprey and other colorful fish. MY SNORKELING ADVENTURE began in a parking lot at Mile-0 of the French Broad River, which flows across more than 200 craggy miles in western North Carolina and into eastern Tennessee. It was a sunny day, and Kevin Merrill, who would serve as my guide, asked me to meet him there so he could gauge the conditions and figure out where to start. Over the weekend, heavy rain had fallen across Transylvania County, so the river was running higher than normal. I followed his white Subaru through the town of Rosman, N.C., where Mr. Merrill grew up and later worked at the public high school before starting Oxbow River Snorkeling along with his wife, Christie.

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