Like a goat being swallowed by a boa constrictor, post-World-War-II baby boomers have distended both social mores and corporate business plans. Cruise lines, for example, have grown passenger loads tremendously for the past decade by reaching beyond from their traditional retiree customers to draw in the baby boomers. North American demand for cruises more than doubled from 5.9 million passengers in 1998 to 12.4 million last year, as the average passenger age fell below 50, according to the Cruise Lines International Association. European passenger growth has been even faster, tripling to 3.4 million over the decade to 2006 as the average age dropped from 56 to 54.

The industry expects double-digit growth or approaching it to continue in Europe and the US. But demographic forecasts suggest that the industry may have to abandon its youth agenda to make this a reality. Baby boomers, currently aged 44 to 62, are headed for retirement. As a result, the annual increase in the US population aged 50 to 65 will fall from the current 3 per cent rate to about zero by 2018, according to US Census projections. As the baby boomers move into the over-65 category, cruise lines may have to retool. Extra medical care and services for those with limited mobility could replace the current rage for climbing walls and wave simulators.