Oh no! All that training and I end up a belly flop

Dom Joly survives snow, a courtesy car, and a glamorous assistant to make a splash in 'Splash!'

Dom Joly in mid-flight on Splash! (ITV)

I was on the ITV show Splash! last night. If you didn't see it then you should know that it's a TV show with a huge tongue in a large cheesy cheek, in which Tom Daley teaches 15 "celebrities" to dive. After three weeks' training, last night was judgement day. People ask what the most nerve-racking part of diving from the 10m board is. The answer is the 24 hours that you spend beforehand worrying about it.

Television people panic a lot and with a live show they like to have the "talent" corralled as early as possible. If they had their way you'd be brought in and locked in a small caravan at least three days before a show so that they can keep an eye on you. The one thing that being in TV for a while has taught me is to fight call times tooth and nail. I was very badly snowed in on Friday and couldn't get to Southend for my final day's dive training. This totally freaked out the producers, who decided that they would send a 4x4 to fetch me from the Snowmageddon of the Cotswolds and "overnight" me in Luton's finest hotel. I said no, as all that would happen would be that I'd sit in a soulless hotel room and worry about the next night's show. I asked them to pick me up in a 4x4 yesterday morning so that I could spend the evening at home in the bosom of my family/in the village pub drinking away the fear.

So yesterday, the day of the show, I awoke to the sight of a very luxurious car that was very much not a 4x4. I knew this, not because I'm a car expert, but because it was stuck in the snow in my courtyard and the driver was digging himself out with a shovel. After a hair-raising drive to Luton, I eventually arrived and went straight into rehearsals. This meant trying on my tight Lycra costume, selecting a hideous dressing gown and then walking through the shots with a stunt diver actually doing the dive I would be doing later. Obviously, he did a fabulous dive that only made me more nervous. Fortunately, I don't think I was the only one with the jitters. All five contestants in my heat had little trailers lined up next to each other and all I could hear all afternoon was the sound of chemical toilets being flushed …

My wife and kids arrived at five o'clock and were shown to their seats. It felt a bit like giving them tickets to see you fight for your life in the Colosseum. All I wanted to do was not embarrass them too much and to survive my 40mph plummet from the top board. Linda Barker won the dress rehearsal and Donna Air came second. I was booted off – was this what was to come for real? I was in two minds as to what to feel. I'm very competitive and hate to lose, but I'd just seen the schedule for next week. There are only 10 high dive boards in the UK and I appear to live as far away from any of them as is possible. This meant that my next week involved six hours a day in a car and a lot more pain.

Then it was showtime … the moment the title music started I could feel the nerves. I tried to control them but it was like a wave of anxiety punching me repeatedly in the face. Everything went into a bit of a blur. I wasn't really there, in a overgrown convict's outfit and a spangly dressing gown about to hurl myself off a cliff. Then I heard my name being called; people were cheering, a model stepped out of nowhere and took my robe off. I started high-fiving people I didn't know.

I floated across the pontoon towards the diving board as a VT played insinuating that, after a promising start, I had reached an emotional crisis in my short diving career. I was now on top of the 10m board and everyone looked very, very small. Vernon Kay said something to me and then a green light flashed to indicate that I should dive. I forgot everything and hurled myself off the board and smashed down into the water far below, the worst dive I'd done in the entire three weeks of training.

The good news was that my back wasn't broken. I didn't get through to the semi-finals. I was disappointed but my work here was done, and I was off wandering alone down the curious road of show business towards God knows where …

Saturday night turkeys

Splash! has been roundly panned by critics. But if you think it's bad, then you can't have seen these:

Pets Win Prizes, 1990s

Danny Baker and Dale Winton oversaw the chaos as punters and their pets tackled challenges. Gone after three series, dog snooker wasn't as popular as it first sounded.

Ice Warriors, 1998

Dani Behr presented. It didn't make it to a second series.

Celebrity Wrestling, 2005

Two teams of celebrities grappled. It was hiked off ITV's prime-time slot after five miserable weeks.

Don't Scare The Hare, 2011

Swiped off BBC1's Saturday-night schedule before the end of its run, contestants took quiz questions and physical challenges with the bizarre aim of not frightening a giant, robotic hare.

Red Or Black, 2011

Simon Cowell's £15m game-of-chance, fronted by Ant and Dec, failed to match the viewing figures of Britain's Got Talent and I'm a Celebrity...