A free diver has said he "couldn't believe his luck" after spotting a giant jellyfish off the Welsh coastline.

Iestyn Morgan, from Pembrokeshire, said the lion's mane was the "length of a bus" with a size of about 10 to 15 metres (32ft 8in to 49ft 2in).

The 21-year-old conservationist, who records footage for social media to raise awareness about the "threats our seas are facing", said it was the first lion's mane he had seen in Wales.