For more than 40 years, British explorer Colonel John Blashford-Snell has proudly worn a Zenith el Primero chronograph on his expeditions across the world. It was first worn when he led The Scientific Exploration Society’s great British Trans-Americas mission in 1971 – 29,000 km from Alaska to the Tierra del Fuego (Land of Fire) through the previously impenetrable swampy jungle of the complete Darién Gap.