Your stock speedo system will drive you mad. Your hair will turn grey and fall out. Your blood will boil and your stomach will churn until you put Perfect Pass on your boat. I'm just sayin........You need an accurate speedometer and the stock one sucks. Plus, it's like getting a new boat when you pull someone for the first time with a good speed control. Our boats need it due to the low torque to weight ratio. It takes a lot of throttle movement to keep a steady speed with any weight in the boat.