Cecil Stockley, a tour boat skipper in Newfoundland and Labrador, uses a unique formula to estimate the length of icebergs he encounters and keeps his boat at least five times that distance away. Dave Boyd, another skipper, has his own safety rules depending on the type of iceberg he’s dealing with. Barry Rogers listens to icebergs and the sounds they emit when the air bubbles they contain escape. Rogers pays close attention to the sounds they make because they can indicate that the iceberg may be about to roll over or split apart. The eastern coast of Newfoundland and Labrador is known as Iceberg Alley, and each spring, icebergs calved off from the Greenland ice sheet pass by on a journey southward to the open waters of the North Atlantic Ocean. Despite the iceberg’s infamy, most melt as they move south into warmer waters and don’t hit anything, but they present a spectacular show to tourists, along with one of the greatest concentrations of migrating humpback whales and half a million Atlantic puffins found anywhere. Along with the icebergs, the birds and whales make for Newfoundland’s unique tourist attraction, usually visible from mid-May through the end of June.