Ben Duncan on filming famous adventurers in some of the world's most dangerous seas.

The brief for Top Dogs: Adventures in War, Sea and Ice was to take three of Britain's greatest adventurers and get them to experience the different environments where each found fame and glory, as a team.

The first trip took the three men - Ranulph Fiennes, the polar explorer, John Simpson, BBC world affairs editor, and Robin Knox-Johnston, the first person to sail single-handed around the world - to war-torn Afghanistan, Simpson's world. The third involved trekking in the Arctic, Fiennes' domain. I was charged with the second trip, which focused on Knox-Johnston's area of expertise. It involved sailing around Cape Horn, in the treacherous Southern Ocean. Even with an experienced sailing crew this would be a challenge. But Ran and John had never sailed before, so we had the ingredients for an exciting, even risky film.

The “top dogs” trained in the Solent to use life rafts, flares and survival suits. The production team learned how to use a defibrillator: Ran had a major heart attack a few years ago. If he had another on this trip it would be up to us to keep him alive.

We were filming on Sony DSRs and Z1s. I anticipated the attrition rate for cameras could be quite high, so we left armed with two DSRs with stabilising lenses, four Z1s and five bullet cameras to place around the yacht, allowing us to capture sequences in the likely event that conditions would prevent the crew from working.

As we were using BBC cameras, our main costs were the excess baggage to Ushuaia, Argentina - the world's most southerly city - and the two yachts we were chartering for the trip. The “dogs” would be on Pelagic, a 60ft steel-hulled yacht, with myself plus a sound recordist to capture the action on board. Another similar-sized yacht with cameraman Tim Butt on board would film all the boat-to-boat action with a stabilising lens.

The main problem in producing a film based on a relatively small sailing yacht, is how to keep things varied. Additionally, we had a very tight schedule to get around Cape Horn and catch our return flights home for Christmas.

I decided we had to get off the boat during the trip to offer the audience an alternative to life on the ocean. This proved to be a point of tension between myself and Robin, who was concerned that we wouldn't have enough time to round the Horn. I argued that if we were prevented, it would all be part of the story. He wanted to be remembered as the first person to sail single-handed and non-stop around the world, rather than the man who couldn't get Ranulph Fiennes and John Simpson around Cape Horn.

After a lengthy discussion over a bottle of Robin's favourite whisky I managed to win him over and we set sail into the Southern Ocean on what must have been one of the best adventures I've ever had.

Top Dogs: Adventures in War, Sea and Ice
Production company BBC Wales
TX starts BBC2, 27 March at 9pm
Producer/director Ben Duncan
Editor Rupert Troskie
Series producer Jobim Sampson
Executive producer Ludo Graham
Summary Three iconic adventurers - John Simpson, Ranulph Fiennes and Robin Knox-Johnston - attempt to sail around Cape Horn

Ben Duncan: My tricks of the trade

  • Humour and flexibility - this has to be the number one requirement. As soon as it's absent the whole atmosphere changes for the worse

  • Cine Saddle camera bag - perfect for a self-shooter, they're ideal as an impromptu tripod and for getting unusual angles
    Cable ties - for attaching mini cams and managing cables pretty much anywhere

  • Empty peli case - safeguards everything you want or need to keep dry and usable

  • Indelible marker - again for the self-shooter, it means no fiddling about with labels