The boat was taking tourists on a bird-watching trip near the South Island town of Kaikōura when the accident happened. Locals said it was unlikely the 28-foot boat had struck debris such as driftwood because there was no damage to its hull. There was speculation that it had been knocked over by a large whale. Almost half of the world’s whale and dolphin species are found in New Zealand waters, including sperm whales, minke whales and southern right whales. Eleven people, including the skipper, were on board when it capsized on Saturday in Goose Bay, near Kaikōura. Craig Mackle, the town’s mayor, said sea conditions at the time were perfect and officials believed a whale had appeared under the boat, causing it to capsize. A local resident, Kevin Anderson, said he spotted a whale within 200-300 meters of the boat after it capsized.