In this video, Glenn Wakefield demonstrates a simple and effective method of sanding using a longboard to fair a boat. Sanding by hand can be hard work and is most definitely labour intensive but will give a smooth and consistent result. Results and the amount of work involved will vary on the type of top coat that has been used prior to sanding.
It is notable that protection should be worn throughout this process: a mask, closed goggles and suitable clothing should be a priority.