‘4,700 species’: Portsmouth exhibition celebrates HMS Challenger’s deep-sea discoveries

Worlds Beneath the Waves at the National Museum of the Royal Navy marks 150 years since ship's remarkable circumnavigation

From the early days of deepwater exploration when it took a crew of 250 to keep the ship steady enough to collect samples, to the modern-day era of hi-tech minisubs, a century and a half of oceanographic missions is being celebrated.

An exhibition at the National Museum of the Royal Navy, Portsmouth has been launched to mark 150 years since HMS Challenger's remarkable circumnavigation of the world in search of the mysteries of the deep - a mission that led to the discovery of thousands of new species of sea creature and the Mariana Trench.