Book 6, Question 122
Why Do Some Boats Have Two Hulls?
A catamaran has two slim hulls joined by a deck. That wide stance makes the boat harder to tip over. And two slim hulls can slice through water with less drag.
From the book
Page from A Million Whys Book 6
More fun facts
- In 2009, a Norwegian tanker with a double hull hit a sunken oil rig in the Gulf of Mexico, yet not a drop of oil spilled.
- The Titanic, like most ships of its time, had just one hull. Many modern ships have two.
- Since 1992, a world agreement has required new oil tankers to be built with double hulls.
- The rule was brought in slowly because changing old single-hull tankers was very hard.
- In Valdez, Alaska, a tugboat once hit a tanker and tore a 4-foot dent in its hull, but no oil was spilled.
Sources: NOAA, NOAA, Smithsonian Magazine
Questions kids ask
Do double hulls really stop oil spills?
Yes. Double-hull tankers have been damaged in crashes without spilling any oil.