Even tough gunners shed a tear as HMS Chatham heads out three weeks before Christmas for a six-month deployment to the Gulf. Then comes news that the vessel is riding the after effects of a massive earthquake that has generated a tsunami.

HMS Chatham reaches the eastern coast of Sri Lanka, which took the full force of the Boxing Day tsunami, as the docusoap following the varied duties of personnel at Devonport Naval Command in Plymouth continues. Thousands of homes have been flattened, untold numbers have died and fishing boats have been hurled far inland - how can the Royal Navy help in the face of abject destruction?

Tasha Pulley is a physical training instructor in the Royal Navy and just over five feet tall. She wants to join the uncompromising and very large men with muscles on their muscles in the Devonport Field Gun Team, whose aim is to win a gruelling race open to all of the Forces. How will she fare?

At Devonport naval base, Ghostbusters are investigating claims the dockyard is haunted. Meanwhile, HMS Chatham sails to Egypt to bury 30 British sailors with full military honours who died 200 years ago when Admiral Nelson destroyed the French Fleet. She then sails north to Turkey to represent Britain at the 90th anniversary of the Gallipoli campaign.

Each Thursday, Plymouth is turned into a war zone as warships, submarines, jet fighters and Royal Marines engage in simulated conflict on land, sea and air. How will Angela Thomas find time for her opera group's production of HMS Pinafore?