The morning after a Royal Navy submarine left Plymouth Sound in Devon, dolphins were found beached in shallow waters around Falmouth Bay. Experts are investigating whether the dolphins suffered a disturbance caused by the submarine. Tests showed the animals were fit and healthy, with no obvious injuries. Dolphin experts are convinced the creatures fled to shallow water after a disturbance at sea. The Royal Navy admitted testing sonar equipment on a warship 12 miles out to sea – but says it is âextremely unlikelyâ it was to blame for the strandings. Studies have shown that sonar can scare dolphins to the surface, causing potentially fatal bubbles in their blood vessels.