Displacement–length ratio

Displacement-length ratio is like how much space your bathtub takes up compared to how long it is. Imagine you have a small bathtub that can hold a little bit of water. It wouldn't take up much space in your bathroom, compared to a really big bathtub that can hold a lot of water. The big bathtub would take up way more space than the small one.

The same thing applies to boats. Displacement is how much the boat weighs and how much water it pushes aside when it floats. The length of the boat is how long it is from the front to the back. The displacement-length ratio is like how heavy the boat is compared to how long it is. So, a really heavy boat that is not very long will have a high displacement-length ratio, meaning it takes up a lot of space in the water.

On the other hand, a lighter boat that is longer will have a lower displacement-length ratio because it is more streamlined and efficient at moving through the water. So, the lower the displacement-length ratio, the better the boat is at moving through the water and the faster it can go.