Started with 60 grit. Drew pencil marks over entire boat. With long board against grain did 45 degrees to right until pencil marks gone, then 45 degrees to left removing next set of pencil marks. Finally 60 grit with the grain removing another set of pencil marks. Left plywood at this stage and only worked on sapale boards on sides, bow, and transom. Again using pencil marks to be sure I did entire surface, used 80, 100, 120 and lastly 150 grit with the grain. I was going to stop at 120, but I am using General Finishes gel stain and they say to sand to 150, so 150 it is. This was a very long tiring process. I need to find a power assisted way of doing this instead of a manual long board. I have also rounded the edges to prepare for fiberglass.
In my opinion, that's exactly how it should be done. Very nice concise description.