The UK Royal Navy's aircraft carrier HMS Illustrious is undergoing two months of operational sea training off the south coast of Britain.
The 22,000t ship has recently undergone a £40m refit to transform it from a warship to a commando and helicopter carrier.
The operational sea training will involve handling battle damage, crashes on deck, machinery fires and incoming aerial threats.
Lynx and Merlin helicopters will also participate alongside the carrier in the sea trials.
The ship will replace HMS Ocean as the UK's on-call helicopter carrier early next year.
HMS Ocean will then undergo a refit programme before rejoining the fleet in 2014.