Hull Contact Surface Finish

Hull bottom Finish

There is some debate as to how smooth the planning surface of a hull needs to be, but in reality these surface finishes are measured in microns, well past what home modelers can do. 

But do we want a smooth surface, dimpled surface or a slightly rough surface? Well the answer is in surface wettability.  Wettability is more important than a perfectly smooth sub micron smooth finish. 

Why? well at the speeds we run our boats there is less friction between water to water contact than there is between water and our boats surface regardless of that surface finish.

What we want for best performance is for the hull surface to be wet with water, rather than covered with a water repellant car wax. We want a surface that water doesn't bead up on but instead wets it evenly like the left side of the above picture.  If your hull does what's on the right, then try again since that represents friction.

One option is to use a coating product that promotes wettability such as Hyspeedcoat.  This is a water insoluble polymer coating that actually holds a continuous film of water on underwater surfaces. The resulting effect of water against water is reduced resistance (drag) and increased efficiency.