NCL Cruises and the Lego Group have challenged youngsters (and the young-at-heart) to compete to win a free Caribbean cruise for their family by creating their vision of the "ultimate cruise ship" using only Lego bricks.

Since rules for the NCL Lego Cruise Ship Building Challenge say you can make the model "as big and as creative as you want," there's no telling how large the cruise ship models will have to be to have a shot at winning a week-long cruise valued at $2,500.

While two of the contest age groups are clearly aimed at youngsters (six to nine, and 10 to 14), the third age group (15 and older) could well attract Baby Boomers who last played with Legos in the 1950s and 1960s.

Even in this era $1,000 will buy a lot of Lego bricks, and one can only speculate how much Lego and cruise enthusiasts may decide to invest in a shot at one of the three free cruises.

"We look forward to seeing how contestants bring their imaginations to life and rewarding the winners with a Freestyle Cruising family vacation," said NCL CEO Colin Veitch.

Ship builders can enter the contest by submitting a color photo of their creation along with a 500-word essay describing their masterpiece before November 9, 2007.