How do I true my hull?

Does anyone know how to true a hull by hand for better top end? I hear of good and bad hulls- how do you check for this and repair?

Better top end? Definitely better handling. I don't know about top end. Can you find a copy of the SeaDoo racing handbook? It has a whole section on hull truing. Basically, they say to go over the hull from bow to stern with a long board sander to find the low & high spots. Sand down the high spots and fill the low spots. I usually lay a straight edge along the strakes to make sure they are true. Often they are wavy. Also, I fair where the hull meets the ride plate so's there's no lip. I've tried setting the boat up as level as possible upside down and shooting the four corners with a transit to see if the hull is twisted. I haven't had much luck.