While I knew it was safe—or should be, anyway—the whole situation was still a bit intimidating. Moments before, when this stretch of almost-neon aquamarine was quiet, the tropical sun reflected off the surface of the blue Caribbean—those warm waves inviting me in for a swim. But now? It was a feeding frenzy. With guides chumming the waters, suddenly the sea swirled with life—specifically, sharks and stingrays. And while my desire for a dip had been replaced by a dim sense of dread, I knew I needed to get in there. It was now or never—and never wasn’t an acceptable option. Securing my snorkel and mask, I took a deep breath and slipped into the maelstrom below. I was at Shark Ray Alley in Belize, a diminutive country—a little smaller even than the state of Vermont—and the only English-speaking nation in Central America. Since it reopened to visitors last October, guests …