On a hot August evening, two weeks before our holiday in Cornwall, my wife told me that our marriage was over. Apparently, she had fallen in love with the handyman who had been working on our house. I double-checked the list of jobs that he had been asked to do; there was nothing on it about seducing my wife.

At first, I assumed that we would abandon the holiday, but it was already booked and our three boys were looking forward to going away, so Kate and I painted on our smiles and headed west.

I had mixed feelings as we set off. While saddened by the thought that this would be our last family holiday, I had never liked Cornwall - the grey skies, the shabby towns - and would be glad not to have to go again. We had been holidaying there for the past 10 years because our children are keen surfers, introduced to the sport by Kate's father, Harry. He loves the place and not only joined us most years, but helped with the bills. When you're a bit strapped, that's a strong incentive to return.

The boys were pretty miserable on the long trip down, so we tried to amuse them with games. One of these was Countries of the Alphabet. The first player thinks of somewhere beginning with A, the second a place that begins with B, and so on. On my turn I said "Canada", and then we waited for our 10-year-old.

"Jack," I coaxed, "can you think of a country beginning with D?" He stared grumpily out of the window.

"Divorce," he replied. Before I could answer, his older brother picked up the theme: "Estrangement!"

"Um, no - but that's a really good word, well done!" I said trying to focus on the positive.
 
Eventually, we arrived at Watergate Bay, a large sandy inlet on the north coast, a few miles from Newquay. The morning was grey and damp. As we unfolded ourselves from the car, families were drifting away from the beach, clearly having decided that the steady drizzle was not going to let up.

The boys, more cheerful now that we had arrived, couldn't wait to pull on their wet suits and race into the sea. The Atlantic breakers that roll in ceaselessly make Cornwall the surfing capital of Britain; and the beaches in and around Newquay are, in my opinion, the best of all. The town hosts a couple of international events each year for professionals but the gently sloping beach at Watergate Bay, patrolled by vigilant lifeguards, is also perfect for families.

Surfing, I discovered, is ideal for couples who are splitting up. I'm surprised that it isn't mentioned in the tourist brochures. While trying to catch a wave (and avoid a mouthful of salt water), I could forget about my wife and her lover. During the quieter moments I bobbed around and contemplated the idea of letting the tide carry me off.

Most people in the water lay prostrate on bodyboards that skimmed them into the shore. But at either end of the bay were the real surfers, with obligatory bleached hair and battered VW camper vans perched on the hills above. They would straddle their boards and wait patiently until the perfect wave approached, and then they would be up and, for a few sublime seconds, slicing through the sea.

Our oldest son, Bill, is 13 and almost good enough to join these kids. In a few summers, he will be setting off with a board strapped to his own van, and I don't discourage this. There are worse ways to spend a gap year, but I do discourage him from heading for Cornwall. I tell him about the fantastic beaches around Biarritz, the exotic coastline of Morocco, the hedonism of Queensland. These are places where, when he's not surfing, he can taste foreign food and meet foreign girls and where the nights are so warm that he can sleep under the stars on the beach.

A couple of minutes after checking into our hotel, I thought about sleeping on the beach, too. The hotel was cut into a hill and our room at the back faced sheer rock, so that it was permanently gloomy. Five beds were crammed into it - when everyone was moving around it felt like being in Selfridges during the sales.

During the next few days, the holiday took on a surreal edge as the hotel's shortcomings revealed themselves. Rather than irritating, however, they proved welcome distractions from our grim pretence of playing happy families.

That first afternoon, after a bracing dip, we raced back to our room, damp and shivering and squabbling over who was going to be first in the bath. As it happened, no one was because there was only a thin trickle of brown water coming from the tap. I went down to reception and was told by another guest that I was lucky - nothing was coming out of his. "Ah, that's your problem, then," the receptionist said cheerfully. "Everyone's trying to use the hot water at the same time. If you could just wait a while . . ."

We cleaned ourselves up as best we could. We are an uninhibited family, used to barging in while someone else is using the bathroom, and so it was an odd sensation for me when Kate pushed the door shut as I approached. The threads of our life together were unravelling more rapidly during our week in Cornwall.

I took the boys downstairs, got them drinks from the bar and then we played pool. After losing to Charlie, our six-year-old, I returned to the room to fetch a book to read. As I let myself in, I heard my wife say hurriedly into the telephone, "Got to go. Call you later." She did, indeed, call him later - again and again during the next few days she would disappear for up to an hour at a time. I wouldn't have minded, but telephoning from a hotel is not exactly cheap.

Having failed the hot water test, I wondered how the hotel would do in the demanding food-on-a-plate competition. Although the dining room was nearly deserted, and the menu limited to only three dishes, the chef seemed unable to keep up with the pace. After bringing our vegetables, the waiter disappeared into the kitchen - to fetch our pork chops, we assumed - but was gone so long that we ate our carrots and peas as a starter.

At the end of the meal, I drained my coffee and beckoned the waiter. "Could I have another cup, please," I asked, holding it up to him. He paused and looked at me, then took the cup into the kitchen and returned a moment later with a different one. I smiled patiently. "Actually, I meant, could I have another coffee."

The next morning we were joined by Kate's father, plus her brother, his wife and their three boys. We had holidayed together many times before and had always got along, but this time the strain was palpable. I felt like I was staying in Fawlty Towers: against a backdrop of chaos and incompetence, everyone was trying desperately not to mention the war. But the artificial jollity merely put us all on edge.

At breakfast one morning, my sister-in-law was reading a newspaper. "Oh, look," she cried, "Noel and Meg are splitting up as well," and then bent to rub the shin that had just been kicked. "As well as Liam and Patsy," she added, glowering at her husband.

Occasionally, I would go for walks along the coastal path or jump into the car. One day, I drove to St Ives to visit the Tate Gallery. I hadn't been for a couple of years and had forgotten how difficult it is to park in the town. In the 15-minute walk from my Pay-and-Display spot, the wind turned my umbrella inside out and the stair-rod rain soaked through my summer mac.

I had also forgotten how small the gallery is. Apart from a few ceramic pieces, there was room to exhibit the work of only two artists, both members of the euphemistically named Naive school. I wandered around trying hard to appreciate the work of Alfred Wallis and James Dixon. It occurred to me, though, that if I wanted to look at pictures of boats or ploughed fields devoid of all perspective, scale and composition, I could just as easily pop into my youngest son's classroom and study the handiwork pinned to the walls there.

It was still raining when I returned to the hotel. I couldn't wait to go home. Kate was in reception booking next year's holiday. She wrote her name on the form, then added his.

Old habits, it seems, never die - just relationships. I felt a pang of regret as another thread unravelled. But, as the rain beat down harder, I reminded myself that at least I wouldn't have to come to this sodden corner of the country again. I looked out at Cornwall's ubiquitous clouds. For once, they had a silver lining.

This article appeared in the Daily Telegraph Travel section

BAY WATCH: Jamie Oliver's restaurant Fifteen, in the foreground, and the imposing Watergate Bay Hotel behind it make this a popular resort with families. Well, families who aren't falling apart, anyway

GATHERING CLOUDS: The mood of the holiday was reflected in the glowering sky typical of Cornwall's frequently chilly and damp summers

MAKING WAVES: Novices and bodyboarders occupy the central part of the long beach but at either end were the real surfers, with obligatory bleached hair and battered VW camper vans perched on the hills above

SMALL IS BEAUTIFUL: The elegant lines of the Tate Gallery at St Ives