The rookie paraglider, on just his second solo flight, had taken off from a Picton hill summit in "perfect" conditions.
The 49-year-old was concentrating on using the building breeze to go higher than he'd ventured before.
But before he knew what was happening, the Cook Strait wind had picked him up and was streaking him across the sky at an estimated 50 knots.
"I was having a great flight, going higher and higher, thinking 'This is fantastic'," said the Royal New Zealand Air Force aircraftman.
"But by the time I tried to go down, the wind had picked up and I couldn't go down - I was still gaining height. When I saw I was headed for the sea, I thought, 'I'm going to drown'."
He tried various techniques to drop altitude during Sunday's flight but nothing worked.
Vomiting and fearing for his life, he searched the Marlborough Sounds horizon for a likely landing spot.
He used a UHF radio to contact his wife Sheira, who was wondering what was going so badly wrong, to say he was aiming for a small Picton aerodrome.
But as he passed over a ridge, a katabatic airflow - one that carries air down a slope at high speeds - "rushed me to the ground pretty quick".
With the ground fast approaching Mr Hudson aimed for open farmland. Turning his back to the wind to try to reduce his speed, he hit the ground backwards.
"It was a hard landing, and certainly hurt my back."
But his ordeal was far from over. He was "physically unable to move, except to dry retch" and, exhausted, soon fell asleep in the long grass.
"All I could do was sleep and wake up and try to get up. It was a really surreal feeling.
"I knew people were looking for me, I knew I had to get up and do something, I just couldn't physically do it. As soon as I lifted my head I would be dizzy, and sick, and just be exhausted."
He finally managed to stagger a few steps, get cellphone reception and phone his worried wife. Then he spotted a rescue helicopter and made contact by his UHF radio.
Amazingly, he escaped with a sore back and a few bumps and bruises.
"I feel that the consequences could've been much worse. I was fortunate there was an open field for me to land in, and fortunate I didn't fly into any high-tension wires or a bunch of trees or land in the sea.
"There were so many factors that could have gone really against me. Had I been more experienced, I hopefully would've picked up the change of winds quicker, instead I was concentrating on flying as high as I could. I didn't twig to that until it was too late."
Mr Hudson had taken off from Collins Hill, near Picton, about 1.15pm intending to land at Koromiko.
Almost four hours later a friend reported he had not returned and the Nelson Marlborough Rescue Helicopter was scrambled.
He was found on farmland at Robin Hood Bay, Port Underwood a staggering 30km off course.
Marlborough police area commander Inspector Simon Feltham said Mr Hudson was fortunate to have walked away with minor injuries.
"This incident underlines the importance of ensuring you have checked the weather conditions and have the skills and experience to match them," he said.
Tasman Hang Gliding and Paragliding Club president Peter Allison said such incidents are "very rare".
"It sounds like he lost a fair bit of control. There's an expression we have in paragliding, and that it's better to be on the ground wishing you were up there, rather than being in the air, wishing you were down there. I suspect that sort of thing was going through his mind at the time."
Mr Hudson has vowed to "get back on the horse", but his wife is going to buy him a personal locator beacon for his upcoming 50th birthday.
