Huxley and Flapjack: Trouble at Sea

Huxley and Flapjack are enjoying a trip to the seaside when they meet Whizz, who invites them aboard his submarine to search for the shipwreck of the Isabella. Huxley's excited to go deep-sea diving - he's sure there'll be treasure to find - but Flapjack can't help worrying. What if something BIG and FISHY finds them first...