The team's training ramps up as the tiger shark dive draws near with Danni Washington and Tristan Guttridge revealing that they will scuba dive around an old and eerie shipwreck. While on their most technical dive yet, Lenny Henry and Lucy Punch struggle with their buoyancy as Ross Noble and Ade Adepitan explore the interior of the sunken smuggling ship. Meanwhile, Dougie Poynter, Rachel Riley and Helen George take part in a night dive on the wreck where they have a magical encounter with turtles, but Helen suffers a panic attack