There's something both eerie and poignant about deep-water footage of barnacle-encrusted shipwrecks, and there's something especially sad about the remains of the Ark Royal. The pride of the Second World War British fleet was sunk by a single torpedo in 1941 in the Mediterranean, its final resting place unknown. But three years ago a BBC team set out to search for the wreckage of the near-legendary aircraft carrier. The operation was a success. Here, Dan Snow takes us on a remarkable journey of discovery, looking at the Ark Royal's illustrious history and making good use of contemporary film. But, as always, it's the testimonies of those directly involved that move the most. The documentary gathers together Ark Royal veterans to view footage from the sea bed, and to share their memories of a ship that obviously still has a tight hold on their heart.