RNLI volunteers teams come to the aid of two teenagers stuck in mud on the Humber estuary and a boat that has lost its mast on the freezing waters of Loch Ness.

RNLI volunteers race to the rescue of a shark attack victim, two boys being swept out to sea in a rip current and two fisherman caught by the tide and now stranded in a rising sea.

The RNLI volunteers race to the rescue of a huge cargo ship aground on a sandbank, a kayaker who has set off an emergency beacon, and a horse in danger of drowning in a river.

The RNLI volunteers race to the rescue of the last inhabitant of a remote island, a kayaker in trouble in the North Sea and, on the river Thames, a dog trapped by the tide.

RNLI volunteers race to the rescue of two five-year-old girls blown out to sea on an inflatable and a mother and daughter trapped by the tide, while one crew member saves his own dad.

As storm Ophelia hits the British Isles, on the south east coast of Ireland the pagers of the Rosslare crew go off - a small yacht with three people on board is caught in one of the worst storms in living memory. In Devon, the crew at Appledore race an incoming tide to try and reach a man stuck fast in quicksand, while on the north coast of Cornwall the crew of St Agnes must battle through huge breaking waves to reach two young boys being swept out to sea in a deadly rip current.

The volunteers of the RNLI race to save three kids caught in a cave by the rising tide, a yacht caught in a storm, and search for a pensioner missing for several hours.

The volunteers of the RNLI race to the scene of a plane crash on a busy beach, search for a man missing at sea in the Channel Islands and battle to save a horse from drowning.

There are many reasons why the thousands of yellow-wellied volunteers first joined up, but they all share a common desire to help those in trouble. At Anstruther station in Scotland, one of their newest helms, George, takes charge for his first shout to a serious medical evacuation. A woman has slipped on one of the most notorious parts of the station's patch, the Chain Walk, where walkers have to negotiate steep cliffs while hanging on to chains hammered into the rock. On the north coast of Devon, the crew at Appledore station make a life-or-death dash to rescue two teenagers caught in a cave being flooded by the tide and pounded by waves, but arriving at the scene they discover that saving the young couple will mean putting themselves in danger. And when Storm Henry hits the British Isles and has shipping running for safe harbours, a cargo ship loses all power and is left at the mercy of the waves and 90-mile-an-hour winds. As she drifts inexorably towards the rugged cliffs of north Devon, two lifeboats are launched but even with their combined power they face a losing battle trying to tow the huge ship out of harm's way

In Torbay in Devon the seas are often crowded with sailing craft of all shapes and sizes – when two collide the Torbay lifeboat crew are called out to provide emergency medical assistance for a potentially life-changing injury. On the south coast of Wales, the Porthcawl crew have just seconds to spare when two teenagers on holiday get caught on a rocky outcrop by a large swell and a rising spring tide. While in Yorkshire, the Flamborough crew have to pluck a man from danger after he jumps off a hundred-foot cliff for a dare.

The volunteers of the RNLI race to rescue a stranded porpoise, a teenager trapped by the tide on a rocky outcrop and the crew of a fishing boat on fire.

The volunteers of the RNLI race to save two paddleboarders being swept into a shipping lane, search for a missing fisherman and abandon a crewmate’s wedding when the pager calls.

The RNLI volunteers race to the rescue of a diver found unconscious 30 metres underwater, a yacht sinking in the middle of the Channel and a windsurfer caught out in a storm.

In Brighton the crew are called out to what they think is just a routine job - towing a yacht that has lost power back to harbour - but a sudden spring squall and mountainous waves leave the crew fighting to save the yacht and themselves from being dashed on the shore. Off the east coast of Ireland, the crew of the small fishing village of Howth respond to an emergency call from a family on a local beach - a teenage girl out on a sailing dinghy has capsized and is now being swept out into the Irish Sea. While on the island of Anglesey, the crew of Moelfre are also heading out to help a family in trouble - two women have swum out to save a friend's young son being blown out to sea on an inflatable, but it quickly becomes the rescuers that need saving themselves

In Tenby, police searching for a boat thief call for lifeboat assistance. The Mumbles lifeguards and lifeboat crew race to help two kayakers adrift in a boat laden with beer. And when two yachts capsize off Portsmouth, the crew must make fast decisions about who to rescue first.

In the first episode, a retired nursery teacher gets herself into danger when attempting to rescue her two dogs after they became cut off by the rising tide. In Wales, one volunteer crew member is washed off a cliff into the sea trying to rescue a concussed spearfisherman, and, in Blackpool, a rescue in a force seven gale goes badly wrong, putting all three crew members' lives in jeopardy. When torrential floods hit Cumbria shortly before Christmas the volunteers are again on hand to try and rescue families trapped by the rising waters.

Dermot O’Leary uncovers the story of the RNLI’s heroic efforts in the Second World War, as its crews were called to serve in the most perilous of conditions, saving 6,376 lives.

The RNLI volunteers search for a missing kitesurfer, race to rescue a father and daughter being swept out to sea and try to save all nine lives of a casualty in the Thames.

The volunteers of the RNLI race to save a stricken fishing boat in a force-eight gale, a yacht trapped on a weir in Loch Ness and a puppy that has swallowed a fishing hook.

The RNLI volunteers race to the rescue of a rock climber who has fallen over 40 feet, a paraglider who has crashed into the sea and a man drifting offshore in a toy dinghy.

The volunteers of the RNLI race to save a fisherman from a burning boat, a man stuck in freezing mud, and a walker who, after trying to rescue her dog, now needs saving herself.

For the thousands of volunteers who guard our seas and waterways, saving other people can mean making sacrifices in their own lives. Volunteer and doctor Adam makes a 500-mile round trip every time he puts in a shift at Tower Lifeboat Station in the heart of London, but his medical skills prove invaluable when the crew are called to help the police try and save a man who is stuck under a pier on the Thames with the tide rising. In north Wales, when police officer Vinny isn't patrolling the streets of Rhyl, he volunteers for the lifeboat crew. When the pagers go off one summer evening, Vinny finds himself heading out into the darkness to try and rescue two teenage boys who have chased a wayward football into the sea and get caught in a treacherous current. While across the Irish Sea in Dunmore East, the lifeboat crew's evening is interrupted by an urgent call to a motor boat stranded several miles out and taking on water.

On the north coast of Kent, new crew member Ruth is on board for one of her first ever shouts. Off the Essex coast, the crew of West Mersea station launch to reports of a life raft in the North Sea. 10 miles along the coast at Clacton the crew get a call in the middle of the night to look for two people in the sea.

Keeping watch over the River Thames, the crew at Tower in central London, the busiest of the RNLI's 238 stations, are called to a man reported in the water eight miles downstream. On arrival, they discover a river bus already on the scene and their crew desperately trying to hang on to the unmoving man before he disappears under the water. At one of the most remote stations, Trearddur Bay on Anglesey, the crew are called to an inaccessible coastal fishing spot, where an angler has plunged face first down a cliff onto rocks. With no helicopter available, the crew and their small inshore lifeboat are the only option to get him to urgent medical treatment. While in Portsmouth, gale force winds and a churning sea make a routine rescue particularly challenging.

From first timers at sea to salty old skippers, the wrong conditions can catch anyone off their guard leaving them in need of rescuing. On the east coast of Ireland, the crew of Courtown's inshore lifeboat face one of their most challenging shouts ever - in deep water they must keep a teenage girl with suspected spinal injuries immobile and afloat for 40 minutes, knowing any movement could leave her paralysed for life. Meanwhile on the English Riviera in Devon, the Torbay crew have just minutes to find a capsized kayaker before she is dashed against the rocks, and in Dartmouth, an 81-year-old sailor, fallen overboard in the middle of the night, is left clinging to a rope for his life.

As the summer sun comes out, so do the fun seekers, and crews around the country get ready for action. In Southend, a family of five out sightseeing are a mile off shore and waist-deep in water after being caught out by the tide. The Shoreham crew are paged in the early hours after a drunken festival-goer jumps in the river. And the Brighton crew fear the worst when a man tombstones off the pier at low tide.

In Porthcawl, a fisherman has been dragged lifeless out of the sea by bystanders. The lifeboat crew race to the beach and join the desperate attempts to resuscitate him.

The Aberystwyth crew must improvise when a local paraglider crash-lands at the bottom of steep cliffs. When an adventurous seal is discovered on the steps of a block of flats, Redcar's newest recruit is first on the scene. And in Minehead, a challenging rescue forces an inexperienced crew member to consider her future.

In Bangor, Northern Ireland, crews are tasked to find two teenage paddle boarders, blown offshore towards nearby shipping lanes. The Tenby crew in West Wales must race to a dog who's fallen over a cliff - before worried members of the public attempt to rescue it themselves. And on the North Norfolk coast, the harrowing hovercraft rescue of three young sisters still brings back painful memories for the Hunstanton crew.

Off the packed beach at Blackpool, the crew race after a teenage girl being swept out to sea on an inflatable dinghy. While on the miles of long sandy beaches at Rhyl in north Wales, amongst the holidaying crowds two girls get caught in a deadly current while swimming just a few metres from shore. And on the Cornish coast a woman, trying out the extreme sport of coasteering for the very first time, falls several metres down a cliff face onto a beach with a fast incoming tide.

In Castletownbere, crew member Donagh faces a baptism of fire on his first ever shout as the crew carry out a dramatic rescue of a fisherman who’s suffered a suspected stroke.

In Porthcawl, the volunteers of the RNLI race to save a surfer at the mercy of Storm Brendan. Meanwhile, in Selsey, a family's day out for a spot of paddleboarding goes badly awry when the father becomes separated from his young children, leaving them stranded on a rapidly dwindling sandbank.

In north Wales, the Conwy crew respond to reports of two people - including a young boy - who have been caught out by the tide and are now struggling to stay afloat.

The lifeboat volunteers pluck a fallen climber out of the sea in Wales and is within seconds of falling unconscious. Meanwhile in Scotland, a team rescue a 170-ton fishing boat that is perilously close to the rocks in gale force winds, and in Minehead, three kayakers are swept out to sea as darkness falls.

On Ireland’s north west coast, the RNLI crew at Bundoran race to the rescue of a teenage girl who has been swept out to sea.

On the north Somerset coast, the Minehead crew come close to disaster in a challenging rescue of two walkers cut off by the tide.

A frantic mother alerts the lifeguards after six teenagers are cut off by the tide in Watergate Bay, north Cornwall.

The Blackpool crew receive reports of a man struggling in the water at midnight. It’s vital to get him urgent medical attention.

In Calshot, the RNLI crew are called out to a young man who has lost consciousness in a jet ski accident; when his heart stops, it’s a race against time to bring him back to life.

On the Isle of Wight, the Bembridge crew face a race against time to save an old fishing trawler that’s become trapped on a submarine barrier, and is now taking on water. Just across the island, the Cowes crew embark on a night time search for a missing jet skier. In Anstruther, on the east coast of Scotland, a man is badly injured after falling into the harbour just a few hundred feet from the station. And on the Welsh coast, the St Davids crew work with the local coastguard team to rescue two people who are stuck on a cliff.

In Queensferry, on the east coast of Scotland, an American visitor is caught out by the tide and is barely conscious when the RNLI crew drag him out of the water.

In Humber, the crew must work closely together to pull off the dangerous medivac of a fisherman with a spinal injury.

The Dover crew respond to a mayday for a small boat crossing the English Channel. Then another vessel capsizes, leaving over 20 people fighting for their lives in the water.

When reports come in of a kayaker who has failed to make it back to shore - where his wife is watching on helplessly - the Larne crew race to the rescue.

The volunteers are called to rescue two students who have jumped naked into the River Thames while high on LSD.

Every day around the UK, an army of unpaid volunteers put their lives on the line to try and save complete strangers. Saving Lives at Sea tells the story of the ordinary men and women of the Royal National Lifeboat Institution (RNLI) who, across the country, are ready to launch their boats and race to the rescue within minutes of a cry for help - 24 hours a day, 365 days a year, whatever the weather. Using footage shot on crews' own cameras, this series takes us right into the heart of the action, capturing the unpredictable work of the RNLI in never-before-seen detail. In south west Wales, the Tenby crew race to a kayaker with suspected back and neck injuries after being caught out by a freak wave. Neighbouring Cornish crews must join forces in an epic 11-hour battle to stop a 3,600-tonne coaster breaking up on the rocks. And the Dart and Salcombe crews are astonished to be paged to the biggest shout of their lives.

The volunteers of the RNLI race to rescue a paddleboarder being blown out to sea, a man overboard and two teenage girls trapped on a sandbank and at risk of drowning.

The volunteers of the RNLI race to save a family trapped in their car, slowly being engulfed by the sea, two kayakers close to drowning, and a fossil hunter cut off by the tide.

The RNLI volunteers face a search in one of the worst storms in living memory, race to save three people caught in a rip current and two men stuck on an oil rig's anchor chain.

The RNLI volunteers race to save a teenage paddleboarder being swept out to sea, a sinking cargo ship and a yacht being battered by an Atlantic storm.

The volunteers of the RNLI battle to save a mother and her son who are caught in a rip current, plus a man who has fallen over 100 feet from the top of a cliff.

In Trearddur Bay, the RNLI crew battle through gale force winds and huge waves as they try to save a surfer, as their worried families watch on from the shore. On the same stretch of Welsh coast, the Llandudno and Rhyl lifeboats are involved in a desperate search for a fishing vessel that's reported missing.

On Ireland's south-east coast, the three RNLI crews at Dunmore East, Kilmore Quay and Rosslare battle to save a cargo ship that has lost all power and is drifting towards rocks. In Hoylake, on the Wirral, a vast multi-agency effort is required to rescue a mother and daughter who have got stuck in the mud and, 65 miles to the west, in the coastal village of Porthdinllaen, the crew respond to a mayday call from a yacht five miles out in the Irish Sea that is requesting an immediate medical evacuation.

In Portrush, Co Antrim, the crew race to rescue a boy who has got into difficulties after jumping off rocks, and one of the crew volunteers enters the water to save him. On the Pembrokeshire coast, the lifeguard team at Whitesands Beach join forces with the St David lifeboat crew to rescue someone who has been found unconscious in the water

In Swanage, the lifeboat crew work hand in hand with the specialist coastguard rope team to help an injured climber.

In Lyme Regis, the crew face a frantic search for three fishermen whose boat has capsized in the River Axe. Meanwhile, the Kinsale crew help a skipper attempting to sail across the Atlantic.

On the coast of south Wales, Penarth crew member Tom is called up for his first ever shout when a female paddleboarder is caught out by the tide.

In Eastbourne, on the Sussex coast, a routine day at the lifeboat station changes in an instant when a boat catches fire just outside the harbour.