Norwegian's new ship, due next year, is going to have the first water park at sea to encourage you, as parents, to take the whole family cruising on the Breakaway. Several ships have water slides and the same strategy.
So how many slides does it take to make a water park?
According to the NCL criteria, five. As long as they're full-size slides, it's a water park…okay, an Aqua Park. Enhancing or endorsing that status are twin "free fall" slides on 
which the floor drops from under the suspecting participant who is immediately thrust into a "thrilling loop." Or two participants can race to the finish in twin twisters called The Whip.
This stuff is child's play…because it's certainly not for adults.
Or how about The Plank? It's just what you think it is…walking the plank off the side of the ship, some 17 stories above the ocean and eight feet out from the deck. Only safety straps keep you from doing what disenfranchised pirates used to do. Drop.
The kids who qualify will have the courage. All the parents can do is watch. On the other hand, maybe not.
On one of our first visits to a water park, the son who decided to go "free falling" from a ridiculous height was then about 12. It was terrifying. Not for him, for us.
Given the same opportunity on a ship like this one, we would "break away" and head for the nearest bar.
Royal Caribbean Rhapsody of the Seas
11 nights
November 18, 2012
Sydney, Australia (return): Newcastle, Cairns, Willis Island, Airlie Beach, Brisbane
Inside: $888
Cost per day: $81
www.royalcaribbean.com