This is the terrifying moment a child was swept off a pier by monstrous waves whipped up by the tail end of Hurricane Ernesto - as Storm Lilian barrelled towards the UK.

The boy, believed to be no more than 12 years old, was believed to have been alone when he fell into the sea amid treacherous conditions on Thursday.

RNLI lifeguards are now fearing the worst, as Storm Lillian brings more dangerous weather just in time for the August bank holiday - which is often the busiest weekend of the year on the UK's beaches.

The harrowing incident at Sennen Cove, West Cornwall was captured on camera by Benjamin Elliott - who said it "highlighted the danger" waves and the sea can pose, CornwallLive reported.

He said he hoped his photos would serve as a warning to others - and that the youngster was "incredibly lucky" to have escaped injury.

Mr Elliott told Cornwall Live: "He made it to the end before a large wave hit the pier. He decided to run back but did not time his run well and was struck by a second wave.

"This pushed him off the pier wall, narrowly missing a nasty head strike as he fell into the sea wearing a Dryrobe, fishing rod in hand and sunglasses on."

Thankfully, bystanders were quick to act as the tide surged and waves "were striking the pier". Mr Elliot said four men "braved the water" to rescue the boy.

The boy was described as "incredibly lucky" with the potential for a far more dangerous situation had he been washed to the other side of the breaker, facing multiple waves crashing against it.

Mr Elliott said the lad "was clearly embarrassed by his activity and with a lack of maturity" and claimed he didn't stick around to thank the men who rescued him.

"He was weighed down by his Dryrobe, and was clearly fortunate that others were around," added Mr Elliott.

 RNLI Lifeguards were flying red flags at Sennen Beach at the time - a warning signal that indicates dangerous conditions and that swimming is not permitted. It happened as the tail end of Hurricane Ernesto slammed into the UK - with Storm Lillian coming hot on its heels over the bank holiday weekend.

The region will also experience large spring tides, resulting in extremely high tides in the morning and evenings, increasing water movement and the likelihood of tidal cut-offs - and high waves. The forecast predicts sunshine with strong winds and medium to large surf.

These conditions - combined with the expected influx of visitors to the coast on what is often the busiest weekend of the year - means the charity's lifeguards are fearing the worst.

Guy Botterill, regional lifeguard lead for the South West, issued a stark warning ahead of the Bank Holiday weekend.

He said: "We are expecting some warm weather and fairly rough conditions this Bank Holiday weekend and so it is imperative that if you are heading to the coast you follow the RNLI's advice and head to a lifeguarded beach where our teams will be performing patrols from 10am-6pm each day.

"If you are going swimming or bodyboarding, do so between the red and yellow flags as it is the safest place to do so. We hope everyone has an enjoyable and safe weekend on the coast."