Moment 20ft shark comes within feet of boat off UK coast as shocked tourists watch it swim behind them

THIS is the moment a 20ft shark comes within feet of a boat full of tourists just off the UK coast.

The creeping basking shark was spotted by the tourists onboard as they sailed in the the Hebrides, Scotland, last week.

Operators then managed to capture this footage on their drone, making them realise the shark measured around the same length as the 12m-long boat they were in.

Basking sharks are the second-largest living shark and fish - after the whale shark - and one of three plankton-eating shark species.

Adults typically reach 7.9m in length and can weigh 5,200kg but the magnificent beasts are harmless, feasting only on plankton.

The company, Basking Shark Scotland, posted a video of the experience on Twitter which has gone viral with 347,000 views.

One shark fan said: “You're gonna need a bigger boat…” while another added "It's a 20 footer! 25, three tonnes of him!”.

Experts say they are very common in UK waters during the summer months.

The latest sighting was near the White Cliffs of Dover in August this year when two young boys spotted what they thought was a fin.

Mum-of-two Emma Horne, 30, was at the beach with kids Finley, seven, and Alby, five.

She said: “We couldn’t believe it. The boys were playing in the water so I got them out quickly.

“There were two young boys who spotted it and were clearly scared — they ran away and one of them shouted, ‘is that a shark?’.

“I warned people and a woman quickly called her dog out of the sea. She was worried.

“Finley and Alby were playing with their nets so we told them to get out then watched it from a distance.

"They were loving it afterwards — they asked if they could catch it!”

A fisherman also spotted the same type of shark in Welsh waters earlier in the summer.

Alex Nel, 32, began filming on his phone when he saw a fin poking through the water and heading towards his boat.

However, there is no need to be too alarmed as this type of shark is relatively harmless to humans and feed mainly off plankton.

The Wildlife Trust describes the species as a "gentle giant" and says they can grow up to 12metres (36ft) in length.