Marianne O'Malley discovers it is not too late, too time-consuming, nor too expensive to learn to sail.

For years I've spent desultory moments during long summer days watching sailboats bobbing happily towards the horizon, wistfully imagining myself at the helm.

I'm not talking about serious sailing here, with crews, expensive yachts and competitive skippers, but those little boats that as children we replicated in newspaper and sailed across the kitchen sink.

Since 1972 the Irish National Sailing School in Dún Laoghaire, Co Dublin, has made sailing accessible to generations of children, many without a sailing background. Their evening and weekend courses provide the same tuition for adults.

The school's senior instructor and manager, Gillian Hackett explains, "Our aim is to introduce people to the water in the safest and most flexible way without them having to invest in their own boat.

"In our introductory and intermediate courses we give people a basic knowledge of sailing. They can then go on to join our unique public sailing club to support and guide them while they gain experience and decide if they want to continue."

Hooked, I sign on and on a balmy Monday evening a week later I arrive at the west pier to meet my three fellow "mature" students for the first of our three evenings of instruction.

As Gillian shepherds us enthusiastically through introductions, togging out, and a brief lecture on the rudiments of sailing, she smiles: "I really enjoy it when middle-aged people pluck up the courage to give sailing a try. They're usually really focused and motivated by the challenge."

We all stand a little taller and beam back. Catherine and John, a married couple, are paired with their instructor, and Gillian confides quietly, "Normally I find it better to separate couples unless they're very certain they want to learn together. We had one couple and the laconic husband took every opportunity to make slight but derogatory remarks about his wife's abilities.

"She seemed oblivious but on the last evening of sailing she suddenly jumped up rocking the boat violently, and roared at him 'I've had enough' and then, obviously completely frustrated - threw herself overboard."

Staggering with incredulity, I wonder why didn't she just push him in? (Okay, maybe the staggering is because we've left dry land). But nevertheless I'm grateful that my new sailing partner, Mary, and I are respectful strangers.

We join our delightful instructor, Jonathan, on an 18-foot day-boat called a squib. And then proceed to skim effortlessly around Dún Laoghaire harbour with Jonathan doing all the hard work and explaining as we go "this is the jib, the boom, and this is how you . . ."

His voice recedes as we sit back and enjoy the sensations while a barrage of information and instructions gently sweep, like the wind, right over our heads. Every so often we exchange quizzical glances but then shrugging, settle back to appreciate this new perspective on the harbour, unfettered by our ignorance.

And it's teeming. Sailboats, cruisers, rowers, canoes and the incredibly large and looming HSS, all obeying the (as yet) impenetrable rules of the sea, manage to avoid each other as they busily make their way. Sea lions peep timorously at the passing traffic and then wisely disappear back into the deep. And each evening a group of friendly line-fishermen standing at the end of the west pier amuse themselves by shouting harmless ribald comments at our two learner sailboats.

A magical mist suddenly descends on Dalkey and just as quickly disappears. The call of Curlews sounds ethereal as it drifts across the water. And wind, an element of weather I've barely considered before, becomes our high priority.

Because our pleasant meander as animated cargo doesn't last. Soon Jonathan has us hard at work and "a flapping sail is not a happy sail" becomes our mantra as we aim for markers and simultaneously try to align our boat correctly, all within the confines of the protective harbour. When it's my turn at the tiller my modus vivendi takes a literal turn, and I continuously sail too close to the wind.

Our little squib flaps, veers and shudders to nowhere. Jonathan smiles and murmurs gentle encouragement and instruction while this new nautical language tries to cement itself a little in my consciousness; gybing - reaching - luffing - beating.

And tacking. That means turning the front of the boat 180 degrees. Mary is first at the helm to try, and standing as directed, makes a competent job of it. The boom swings, Jonathan prompts, "Mary, straighten the tiller."

We shift sides, she straightens the tiller as requested, the boat swings and heads in the right direction and surprisingly, we all remain on board. Easy.

Now it's my turn and things start to go awry. The boat is entering its second speedy 360 degree convolution (these boats can really move) when a little steel enters Jonathan's voice "Marianne, straighten the tiller . . . the tiller . . . you know, the thing in your hand. . . straighten it."

My brain is sludge but my body eventually obeys, and so does the boat moving seamlessly in exactly the same direction as before. I plop down, dizzy, disorientated and tangled in rope like Olive Oyl in a Popeye cartoon. Mary gives me an understanding smile - and the comfort of strangers is confirmed.

Despite myself over the following two evenings of instruction I begin to make progress, trailing way behind my fellow students. I eventually get really sick of waving nicely at the smiling (and dry) Catherine and John as they skim past us yet again tacking and gybing to their hearts content and not a cross word between them.

But then, every so often I get it right. We leave the protective arms of the harbour for the open sea. The wind connects with the sails, I connect with the tiller and the mainsheet, and with a jolt and a tilt, a joyous feeling of silent, weightless, effortless power makes me whoop out loud as we whizz across the water. I've discovered I'm not a natural born sailor. Cork Sailing Regatta will no doubt continue without me. Yacht owners will probably never try to lure me as crew, but that feeling will have me signing-up for the next intermediate course. And I'm certain that on some future summer's day I'll be in one of those boats sitting at the helm, bobbing happily and independently towards the horizon.

• The Irish Sailing Association has a comprehensive guide to affiliated clubs and centres that provide sailing tuition. Contact: The Irish Sailing Association,3 Park Road, Dún Laoghaire, Co Dublin Tel: 01 2800239 - website www.sailing.ie

• A weekend or evening introductory sailing course costs € 235 with the Irish National Sailing School and Club, West Pier, Dún Laoghaire, Co Dublin. Tel: 01 2844195 - website: www.inss.ie