The moment I had unpacked, I rushed from my cabin up to deck eight to inspect the pool. On cruises in the sun I like to swim several times a day, even though I know that unless you are on a monster ship, the pools are always a bit of a joke. On my previous two cruises, on ships of a similar size, they had been small but adequate. This one looked the size of our kitchen table. Oh God. Why didn\'t I check? All my fault. I was with Seabourn, on their good ship Odyssey, or yacht, as they like to call it, as they are very classy and superior. But then all of my previous cruises had also been with classy operators - Silverseas and Regent Seven Stars. When I started cruising, just over a year ago, I was told these were the three top-notch cruise lines afloat. And it\'s true. All are the last words in taste and luxury. The food on all three is excellent, with good wines, and as much champagne as you can sup, all part of the inclusive bill, which, of course, is not cheap. Staff can\'t be faulted, and they all have about one worker to every guest. On the Odyssey that night, after a sumptuous dinner, I fell straight to sleep - then straight awake again about 1am. I could hear a couple of Americans in the next suite, talking and laughing. I went out on my balcony, and closed the door, but I could still hear them all night - they kept it up until I was screaming. They weren\'t drunk or playing loud music - just not going to bed at 10pm like normal human beings and sleeping in silence until 7am. In the morning I asked to change cabins - no chance. The ship was full; 437 on board and no spare suite. I told myself that was it, I had done with cruising, I\'d stick to hotels from now on, or tents. But the next night there was silence from the Americans. They seemed to have settled down, though they rarely left their cabin. Goodness knows what they were doing, but I have noticed that on all cruises about a third of guests do nothing and go nowhere, despite all the lavish entertainment. Although I don\'t like games, spas and quizzes and I generally find the music too noisy and uninspiring, I never struggle for things to do onboard because I make a point of meeting as many fellow guests as possible. On this cruise I accepted all dinner invitations that came my way, including one from the Danish captain of the Odyssey and another from a Romanian dancing couple. Funny how, on each of the three cruises I\'ve so far tried, the main dancers were a couple from Eastern Europe. One of the good things about travelling alone on a cruise is that you never need eat alone - the invitations flow in, formal printed cards for dinner dropping through the door, so you feel frightfully important. Most of all, I go on a daily excursion - even when it\'s an extra, which it was with Seabourn. My six expeditions came to £349. I know you can do it cheaper by hiring your own taxi or getting a bus, but it\'s nice to have decisions made and stuff organised, and you can be sure you get to see the best bits. When I am on my January hols in the West Indies, I get furious when a cruise liner arrives, blotting out the harbour and disgorging lumpen groups who clutter up the pavements as they blindly follow some shouter with a flag or umbrella. But when I am one of the lumpen ones, it quite amuses me to be led around. The top-class lines keep the groups small, the guides are good and your fellow guests are of excellent quality as well. On Odyssey, I chummed with a New York lawyer and his wife, the brother of a Belfast peer, an English woman who invents toys and games, a Mexican who owns a football club and our former ambassador to Mexico who, I later discovered, is a Dame. The cruise started from Venice - and the departure was stunning. I have been to Venice many times, but I don\'t remember seeing any cruise ships. Yet we sailed right past all the wonders, gaping into all the palaces. We crossed the Adriatic to Croatia, stopping at Zadar for a tour of the well-preserved old town. The most unusual thing was a modern creation, right on the front - a sea organ. Don\'t ask me how it worked, but they have somehow landscaped the esplanade leaving 35 holes for the sea and wind to blow and surge through and make music. Because of the random nature of waves and wind, the music is always different. Spooky. We did Dubrovnik and Kotor, an amazing walled town in Montenegro.Then on to Greece, stopping at Corfu and Santorini, where I took the cable car up the sheer cliff, scaring myself rigid. At Katakolon I chose an excursion to the site of the original Olympics. I had never realised the site was so huge, more than a mile across, with so much still remaining of the temples, pillars, gymnasiums and athletes\' quarters. The stadium is rectangular so you had to run back and forth. For a long race you went up and down 24 times. I also never knew that the ancient Olympic games, which took place, as now, every four years, attracted athletes from all over the Greek empire - and were held for almost eight centuries. See, cruises can be educational as well as enjoyable. And exhausting. I did so much, talked to so many people, that at the end I was looking forward to rest. And I did get to grips with the pool. If I picked a time when it was empty, I managed ten strokes, going slowly, with the wind against me. My three cruises have totally dispelled the prejudice I once held - that cruises are for the elderly, the bored, the unimaginative.I now know they come in all types and sizes and prices, catering for all interests.