Chris Grimes, 17, hung to the 10ft by four foot Flexifoil Sky Tiger as he was carried across the estuary from St Osyth, Essex, to nearby Brightlingsea.
He said: "I clung on for dear life because I didn't want to land in the middle of the river. It was a terrifying experience because I didn't know when I was going to stop."
But kite experts say while it was a freak accident, it was avoidable.
Kite designer Andrew Jones, who works at Flexifoil's headquarters in Soham, Cambridgeshire, told BBC News Online: "I don't know the exact circumstances behind this incident but I understand the conditions were dubious at least.
'Horrendous conditions'
"We always advise our customers not to fly their kites when it is stormy, or there is a risk of thunder and our products are clearly labelled to that effect."
Steven Howard, who co-owns Force Nine Kites in nearby Clacton-on-Sea, said: "The conditions on Saturday were horrendous.
"These kites are extremely powerful and are designed for traction - for use with kite buggies, which pull you along."
Mr Howard, who set up his kite shop 11 years ago to surf the wave of renewed interest in kiting, told BBC News Online: "This is the first incident of this kind that I have ever heard of but it just goes to show the power of these stunt kites."
Coastguards at nearby Walton-on-the-Naze were alerted and a team was sent to search for the teenager.
Mr Grimes, who was finally dumped soaking wet and covered in mud with his trousers round his ankles, told the Daily Telegraph: "The weather was quite calm when all of a sudden this huge gale came from nowhere and I went straight up in the air.
"At one stage I came down and was dragged along the surface before I was hoisted up again and landed on the other side.
"I reckon it was all over in seconds, but it seemed like a lifetime."
Unregulated sport
Mr Jones said his company made a number of smaller models and he said people were advised not to go straight in at the deep end and buy a large, powerful stunt kite which they might not be able to handle.
He said there were no regulations regarding kites - children under 16 are quite free to buy stunt kites - only recommendations.
Apart from flying them in stormy conditions - kite lines can act as lightning conductors - people are also advised not to use them near electricity wires, airports, cliffs or large bodies of water, unless wearing lifebelts.
Mr Howard said: "If you are flying on the limits then the slightest increase in wind speed can push you over the edge.
"We always say to our customers that if it's a case of the kite or your own life, then let go. Kites can always be replaced."