Vidal, helicopter surveying, and the claim to Rockall

Vidal was a purpose-built survey ship, the first small Royal Navy vessel designed to carry a helicopter, and the last surface vessel built at Chatham Dockyard. Named for hydrographer Alexander Thomas Emeric Vidal, she was especially suited to the 1955 mission that landed a naval, Royal Marines, and civilian party on Rockall. The party fixed a brass plaque to the rock and raised the Union flag to formalize Britain's claim. Helicopter mobility made that otherwise difficult landing practical. Vidal's later work included carrying the Royal Navy's chief hydrographer to talks in Leningrad and transporting Royal Society personnel to Indian Ocean survey sites. Her career therefore links hydrography with sovereignty, diplomacy, and scientific access.