Here’s an odd statistic. In 1999, 15,000 children from the UK went on a cruise holiday; last year, it was 105,000. That’s a rise of 700%, and it simply doesn’t make sense.

As everyone knows, what kids need on holiday is space to run wild; cooping them up on a boat for a week sounds like masochistic madness.

Still, all those parents can’t be wrong... can they? It was that seemingly innocent thought that led me and my wife, with two sprogs in tow, to be standing on a Barcelona dockside, looking up (and up, and up) at Navigator of the Seas, mouths agape, issuing faint gurgles of fear.

Navigator isn’t so much a ship as a small town with propellers. It takes 3,800 passengers at a pinch, looked after by 1,200 crew. It’s 1,020ft long, which is more than three times the length of a football pitch, but a football pitch isn’t 14 storeys high.

Does P&O' s Ventura float a family's boat?

Phil Davies and young family rate the facilities on a Mediterranean cruise aboard Ventura - and finds not all is totally ship shape

• It might be big, but is P&O’s Ventura any good?

Cruise from six British ports

This is an island nation, so why fly to the start of a cruise break? London, Newcastle, Liverpool, Harwich, Oban and Dover feature

Related Internet Links

• Read 150 articles in our cruise section

Your Top 10 cruise questions

From tipping to excursions and walkie talkies - the best of your cruising questions

Related Internet Links

• Read 150 articles in our cruise section

Related Links

• All aboard for a Fantasia cruise

Almost all the growth in family cruising is accounted for by mega-ships such as this. They’re popular because there’s always lots to do. And how.

Navigator has an ice rink, a 30ft climbing wall, a skating track, a miniature golf course and a full-size basketball court, as well as three pools, several kids’ clubs, six restaurants, untold bars, a spa, two theatres, a casino and a nightclub, all set around a piped-music-soaked shopping mall that’s eerily reminiscent of Gatwick’s south terminal.

(There are also two prison cells, whimsically nicknamed Marriott and Sheraton, but they don’t put that in the brochure.)

Overall, it’s busy, busy, busy — and that applies to the colour schemes as much as the teeming public areas. If all this is starting to sound like Not Your Thing, join the club. I asked my wife what she thought. “It’s like someone’s put Milton Keynes on a boat,” she said.

As we wandered, slack-jawed, I asked myself what I had done. I’d cast us adrift on the sort of temple to brash consumerism we’d usually avoid like the swine flu, that’s what I’d done.So it felt rather weird, and not a little chastening, to admit, five days later, that we’d had a really good holiday.

How did that happen?

The key to enjoying a family cruise is simple. Total surrender.For the first day or two, I couldn’t accept this. I sought out healthy options for the children at dinner, quizzed the staff at the kids’ club on what improving activities would be undertaken that day and dragged the children into Cagliari in an attempt to make them appreciate the local ambience (which there wasn’t any of, as we arrived at siesta time and it was “all aboard” just as the townsfolk were waking up for the evening).

Wrong, all wrong. Resistance is futile. Leave the responsible-parenting manuals at home, along with your sense of irony, restraint and higher mental faculties. This is about sheer, unthinking hedonism, for the kids and for you. Here, in appropriately easy-to-use predigested chunks, is my step-by-step guide to having a great time on a family cruise:

Times recommends

• Oasis of the Seas: the Times review
• The 20 best new year party places to stay
• Green Spaces 2009: are you the winning writer?