Thrill-chasers driving motorbikes, scooters, a shed and a monowheel are pitting themselves against sand and tide in a bid to break world speed records on a historic Welsh beach.
Around 60 participants have descended on Pendine Sands, Carmarthenshire, South Wales, which was first used for a world land speed record by Sir Malcolm Campbell in 1924, on Saturday for the Straightliners "Top Speed" event.
Drivers from all over the UK, and some from France and Holland, will test themselves on the sandy one-mile or 1km course in an attempt to break British, European and world speed records.
Each attempt is recorded officially and the record-chasers can have as many goes as time and tide permit, queuing up for a second attempt after completing the first.
Describing why people take part, organiser of the event and founder of Straightliners, Trevor Duckworth, 72, said: "It's like anything, it's the challenge.
"There is a combination of challenges, sometimes it's quite dangerous, there's a challenge there to do it.
"If there's a record there and somebody breaks it, it is like doing any human endeavour.
"There is something to achieve. The other thing that isn't recognised is the mechanical scale and technical ability, people just want to achieve great technical things.
"Pendine has a very, very long history of speed events and that makes it special."
The first person to use Pendine Sands for a world land speed record attempt was Sir Malcolm Campbell who, on September 25 1924 set a world land speed record of 146.16 mph in his Sunbeam 350HP car Blue Bird.
Sir Malcolm, who had the car painted in his distinctive colour scheme, raised it the following year to 150.76mph.
Participants in the modern-day event had to wait until 1pm on Saturday to start for the tide to go out and the sand to be sufficiently dry.
Anyone with a licence to race can enter the event. Mr Duckworth said participants were joined by former MP and defence secretary Michael Portillo on the sands on Saturday.
He said Mr Portillo, who was filming for a television programme, had a go at driving a three-wheeled Morgan on the beach.
Many of those hoping to break records are riding powerful motorcycles, some of them custom-made for the event but some of the motorised vehicles are a little more surprising.
One such unusual creation is the world's fastest shed, owned and driven by Kevin Nicks, from Oxfordshire, which set the record for a hard surface last year, achieving a top speed of 95.808mph, Mr Duckworth said, adding that it was the first time the machine had been on sand.
Meanwhile Tom Anable, from Lincolnshire, will be attempting to break his own world record during the two-day event while driving his monowheel.
Mr Anable set the record in 2015, reaching 43.486mph.
Mr Duckworth said some British records had been broken so far and it took time for drivers to get used to driving on sand, which can be a challenge.
"It's quite a challenge to keep your balance," he said. "It's quite difficult running on sand for all but particularly for the two-wheel vehicles.
"It's a whole other experience than a hard surface - it can slide quite a bit and grip is more difficult."
The event will continue on Sunday and is one of dozens Straighliners organises around the country each year.