Royal Navy survey ship HMS Echo has discovered a previously uncharted underwater 'mountain' on the bed of the Red Sea the size of the rock of Gibraltar.
Yemeni fishermen evidently knew the mount existed – Echo found a dhow anchored on its summit as she carried out her survey of the area.
But existing charts of the area suggested the sea was 385 metres (1,263ft) deep – but over an eight-hour period, Echo collected reams of information with her sounders to prove otherwise.
After processing all that information, 24 hours later the powerful computers aboard the ship produced the stunning 3D imagery which revealed the true extent of the mount.
It rises to just 40 metres (131ft) below the surface of the Red Sea – deeper than the deepest draught of any civilian or military surface ship, but definitely a danger to submarines passing between the Mediterranean and the Middle East.
It is absolutely massive, and finding it is something which really makes everybody on board feel good