July 1984, a Sussex school swimming gala; my 12-year-old self is poised above the sunlight-dappled pool, ready to slice through and glide under the surface like an elegant water nymph.

Sneaking a glance at my competitors, I’m surprised to see them positioned to dive rather than bottom-shuffle off the edge (my trademark style). I can’t really dive. Ah well, arms aloft, knees bent – how hard can it be?

Whistle goes and I spring like a bird through the air..and hit the water horizontally – a plank of wood thudding onto a sheet of thin ice. The impact sends globlets of water over the spectators and shots of pain into my middle. Struggling to regain composure I lumber through the water, more walrus than swan, before finishing 10th. Out of 10.

For the first time in 28 years since that belly flop, I’m bracing myself for a competitive swim.

My friends and I (collectively known as the Merladies) are taking to the water in October, leaving the keyboard and going overboard, making a splash to raise some cash (donate and we’ll stop the crap puns) in aid of a very good cause, a Dares challenge for the learning disability charity Netbuddy

As the sibling of a (very fabulous) sister with a learning disability, the kind of support Netbuddy offers would have been invaluable when we were growing up.

Our aim is to zip through as many lengths as possible in half an hour and improve that total every week this month.

Merladies? Because we’re too mature to be mermaids. Swimming? Apart from the chance to redeem myself, my recent jaw op means my surgeon’s banned me from anything more hardcore than flailing about in a pool. Otherwise we’d be halfway up Everest. Obviously.

We began our splash for cash this week..here’s how it went:

Week one of the big lather household (anyone got a decent water-related Big Brother pun please?) and my fellow fundraiser Dr Ruth Evans, aka Evans the Eel, joins me at the water’s edge.

Eel bemoans the fact she was always in the ‘bottom swimming group’ at school (bottom stroke – new Olympic sport, sounds kinda fun!) but hopes to rise like a phoenix from the flumes, er flames, with the Netbuddy challenge.

I, meanwhile, am looking forward to what will be the most exercise I’ve done in the fortnight since my jaw op (apart from flexing a bicep to mash chocolate cake into easily digestible clumps).

And we’re off! Eel does indeed power through the water and – ah the indignity – swaps from my slow lane into the fast one.

30 minutes later, we’ve totted up 1500m – China’s Sun Yang set a new world record at London 2012, taking 14 minutes to do the same distance so really, by my, um, scientific reckoning, we’re halfway to matching Olympic record! Huzza!

* See our fundraising page for more info and how to donate to our charity challenge, any amount, no matter how small, would be very much appreciated.