Enter the speed of the boat (knots) and the waterline length (ft) into the Calculator. The calculator will evaluate the Speed Length Ratio. 

Speed Length Ratio Formula

SL = V / SQRT(L)

Variables:

  • SL is the Speed Length Ratio ()
  • V is the speed of the boat (knots)
  • L is the waterline length (ft)

To calculate the Speed Length Ratio, divide the speed of the boat by the square root of the water length.

How to Calculate Speed Length Ratio?

The following steps outline how to calculate the Speed Length Ratio.

  1. First, determine the speed of the boat (knots). 
  2. Next, determine the waterline length (ft). 
  3. Next, gather the formula from above = SL = V / SQRT(L).
  4. Finally, calculate the Speed Length Ratio.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

speed of the boat (knots) = 5

waterline length (ft) = 20