The purpose of the block coefficient is to obtain a value that will allow us to say that this hull is X difficult to propel through water compared to a square faced block.

Formula

• Cb = disp / ( LWL x BWL x Hd x 64)

Since we know that our example vessel has a displacement of 10,000 lbs, a LWL of 27 feet, a BWL (max Beam at Waterline) of 8.5 feet and hull draft of 2.3 feet we can calculate that the Block Coefficient, Cd = 0.30

We need to use the Block Coefficient to calculate the Wake Factor.