FIGHTING terrorism, river rescues, escorting warships, searching for missing people and reining in reckless jetskiers... it's all in a day's work for marine police officers working in Essex.

The team covers the entire Essex coastline, from the QEII Bridge at Thurrock to Manningtree, near the Suffolk border - not to mention all the reservoirs, rivers and lakes in between.

PC Dawn Smith says one of her most memorable days as a marine officer was during a bank holiday in 2006.

She ended up rescuing seven people and a dog from a capsized boat, just outside Burnham Yacht Harbour.

She said: "We saw the boat swaying and it just went over, trapping the people.

"I ended up dragging seven people out of the water, including a 76-year-old woman who had angina and a hip replacement."

The rescued people ended up nominating PC Smith for a Pride of Britain award for her bravery.

Equally important is its key role in preventing crime and gathering information about crime and antisocial behaviour.

Fellow marine unit officer PC Jason Lane said: "If the police boats are seen on the water, that's half the battle "We need to deny criminals the use of the water and to do that, we act upon intelligence.

"We routinely stop vessels to see who is on board and where they are going, in a similar way to stopping vehicles on the road.

"We deal with all aspects of marine crime, which includes everything from criminal damage to boats to fraud."

Since the 7/7 bombings in London, the unit has regularly patrolled parts of the Thames where terrorists could strike.

It searches for missing people - a task which can involve the unpleasant job of recovering bodies from the water - and it works with the fire service on planning for flooding.

Based at Burnham's former police station, the unit has two launches and three smaller rhibs - rigid-hulled inflatable boats - stationed at strategic points around the coast.

PC Lane said: "Recently, we were called in to search a part of the river in Chelmsford for a firearm which may have been used in a robbery.

"We used to use police divers for this kind of work, but now we are called in to wade in and search the water by hand, using underwater cameras to help us.

"We found a bag full of stolen property, such as wallets, which we could link to crimes we believed were committed by someone we already had in custody."

But as the summer approaches, the main concern of the unit is nuisance jetskiers - the waterborne equivalent of boy racers - who can often put others at risk by driving the machines dangerously.

PC Lane said: "During summer, there are instances of antisocial behaviour where a minority of jetskiers cause problems by breaking speed restrictions and causing problems through the mooring areas.

"This is mainly due to a lack of education and training, but it is annoying to other river users.

"We are acting this year to prevent and reduce this, from an antisocial behaviour point of view and a safety point of view."

The unit even has its own jetski to allow officers to get up close and personal with jetskiers.

The unit has forged a good relationship with the county's marine community and PC Lane is quick to emphasise being based on water doesn't restrict officers' commitment to community policing in general. He said: "We have two police community support officers dedicated to the marine communities.

"They gather intelligence and attend local yacht club meetings.

"We have a Marine Watch system, which involves encouraging marine users to give their boat details to the police, as there is no centralised registration system like with cars.

"It all helps us know who is who."

The unit also works closely with its counterpart in Kent, sharing resources and information, with officers often training together and carrying out joint operations.

The officers also work with organisations, such as the RNLI and the Coastguard.

PC Lane said: "We get involved in incidents which are not specifically police-related, such as assisting the Coastguard and RNLI with rescues.

"If we are on patrol and someone is in trouble, we will help."

Officers in the unit are highly trained, with ten further officers trained as reserves. They work in other police departments, but spend a couple of days a month with the marine unit, so they can help out afloat, if needed.

PC Lane said: "There is a lot of training and it is a gradual process to build the knowledge.

"On top of that, most officers have extra skills, such as advanced medical or firearms training, marine mammal care and pulsar searching.

"We also have quite a broad base of policing experience for quite a small unit."