08:10OctonautsSeries 4Episode 13: Octonauts and the Tiger SharkCBeebies Sat 27th May 2017, 08:10 on CBeebies HDAvailable for 5 monthsPreschool animation. Tweak must help her friend Sandy the sea turtle escape a hungry tiger shark.GenresChildren'sFactualBrandOctonautsSeriesOctonauts: Series 4 Source: BBC Online