MAN overboard! Man overboard! Action stations. The crew drops everything and leaps to its feet. The radar man plots the ship's location. Another puts his hand out to point to the figure floating in the North Sea. Lifeboats are launched and lifelines dropped while HMS Ocean turns around to head back for the lost sailor.

The whole exercise is carried out rapidly and everyone knows their role.

Fortunately, this is just an exercise and the dummy is safely recovered, but it is part of a rigorous routine that keeps the 380 members of the ship's company on their toes.

Everyday they face one crisis or another that could happen on board the Royal Navy's biggest warship. Fires, floods, falling mariners, every eventuality is accounted for and the crew train meticulously so they can spring into action whenever they are needed.

Many of the crew are teenagers who have signed up for a life in the armed forces for 22 years. Life at sea can be daunting but when 19-year-old Amanda Walker, from Darlington, gets a bit depressed, it just makes her more determined to carry on. She has been in the navy for 18 months now and joined after becoming interested in the armed forces because of family connections.

Amanda says: "It is a big ship but it is easy to make friends here because it has got a relatively small crew and you talk to people who you work with and share messes with. It is a great way to meet new people and learn what they want to do with their life."

Day to day, Amanda starts work at about 8am and finishes at 4pm, although some people can find themselves coping with up to 18-hour days. Her duties involve looking after the officers and making sure all their needs are catered for, such as cleaning their rooms, but her ambition is to become a stoker, or a marine engineer mechanic.

An unusual choice for a teenage girl perhaps, but Amanda is one of 65 women on board who are quite happy to muck in with the lads.

HMS Ocean is a helicopter carrier and can house some of the best aircraft in the Royal Navy, including Chinooks, Sea Kings, and Gazelles.

With a top speed of 18 knots, or 25mph, she can travel 8,000 miles without refuelling.

Ocean was involved in the Iraq war last year and provided the Royal Marines with a launching pad to storm Basra. The ship was also sent to Afghanistan during the conflict to remove the Taliban and as part of the peace-keeping force in Sierra Leone. Her sheer size and military capability means she can be sent to patrol as a show of strength.

Captain Tony Johnstone-Burt, who was educated at Durham University, says: "She is at the forefront of all expeditionary warfare that we can aspire to have. She is a phenomenal creature and comprises all the very best of the three armed services in Britain.

"It is like a fabulous gravy of talent and capability all brought together for a common purpose to project power ashore whenever and wherever we are required by the Government."

HMS Ocean is Sunderland's adopted ship and earlier this week the crew was given the freedom of the city. Stoker Duncan Wilkinson, 21, from Sunderland, has two-and-a-half years service under his belt. He says: "As a homeboy, having the freedom of the city just sends shivers down your spine. I am very proud to bring the ship into my home port."

Duncan has not been home for four months, which he admits can put a strain on his relationship with his girlfriend Maxine. Despite this, he is committed to his chosen career and reckons he will still be in the Navy in 20 years time.

Although Duncan says the food on board varies, the crew is kept fit and well with three square meals a day and the chance to take plenty of exercise. There are running machines on the ship and it has its own swimming pool to ensure all the human fighting machines are maintained.

Duncan says: "It can be hard being away for long periods but every day is different. The good thing is it is a steady job and these days you don't know whether some jobs are safe from one year to the next.

"There is a good social side, great craic with a top bunch of lads and lasses and you can have a drink in the mess. It is especially good when you hit a foreign port and go ashore."

Ocean has recently returned from a voyage to Florida where the crew were able to take some leave and visit Disneyworld and all the other attractions the Sunshine State has to offer.

Ian Pattinson, who was born in East Herrington, Sunderland, has the responsibility of looking after the crew and ensuring they are all happy. This could involve dealing with people who have emotional problems, such as a death in the family, or with those who perhaps are feeling the strain of being away from home.

The 44-year-old Logistics Commander's role is to overcome these issues and he calls on his 26 years of naval experience to do that.

"We have a duty of care and because the Royal Navy injects a separation into people's lives it is up to us to look after them when they are not able to deal with problems like you would normally," he says.

"Some people find it easy to make the transition to sea life but others don't. We are like a microcosm of society and we have all the needs of a small village."

The ship has shops, a post office, banks, a hospital, an operating theatre and a dentist.

Ian says a life at sea is all he ever wanted to do. He enjoys the action man image and has travelled extensively around the world. The North-East, with its strong naval heritage, is a fruitful recruiting ground for the Navy

"Britain has sent mariners to sea for hundreds of years to go and ply their trade and I am happy to continue that tradition," says Ian. "If it was good enough for Nelson, it is good enough for me."