<sod >The moment that aÂ 50,000-pound humpbackÂ whaleÂ pushed her away fromÂ snorkeller to safety from a 15ft tigerÂ shark was captured on camera.< eod>< sod > The moment aÂ 25-tonÂ humpbackÂ whaleÂ pushed aÂ snorkeller to safety from a 15ft tigerÂ shark was captured on camera.< eod>