National Geographic : 1957 Aug
© National Geographic Society + A Wall of Water, the Tidal Bore Roars Up the Petitcodiac River Shoals at the river's mouth temporarily dam the fast rising tide. Oversweeping the obstacle, the crest drives inland like surf on a beach. Height of the bore, Fundy's largest, varies from a ripple to five feet, de pending on the moon. Gulls hover for worms churned up by the turbulence. + Tide Reverses This Waterfall, + Then Drowns It in a Calm Lagoon French explorers in the early 1600's came upon Re versing Falls near Saint John, New Brunswick. "The river takes a fierce leap... with a wondrous noise," they wrote; "at low tide outward; at high, inward." The Zahl children and a guide see words come true as the river moves seaward (above), then inland (below).