A small group of stand-up paddleboarders in the UK are taking the sport to extreme new levels, harnessing the ultra-fast hydrofoil technology seen on yachts in the America's Cup.

The foil works like an aeroplane wing, with the upward pressure of the water lifting the board almost a metre out of the water.

Now, after importing specialist equipment from Hawaii and watching YouTube videos to learn the technique, the UK paddleboarders are mastering the new discipline.

Surfer, ocean paddler and now SUP foil instructor Glenn Eldridge, from St Ives in Cornwall, is one of them.