fishermen set out in motorised vessels to locate the pods of dolphins following their primordial migratory patterns along Japan's south-eastern Pacific coast. Banging on metal poles suspended from the sides of the boats, the fishermen confuse the dolphins' sonar, and drive them into the hidden cove of the film's title. There, dealers size up young females to sell on to marine parks and dolphinaria. The remainder are brutally slaughtered by fishermen using knives and spears in a bloody massacre – which turns the waters red – to be sold either as dolphin, or more often 'whale', meat.