I saw the boat speed indicator on APS (Perfect instrument for tuning up, especially in classes that do not allow knotmeters while racing. Reads boat speed and records maximum speed attained, average speed and distance traveled. Impeller mounts on hull with adhesive, display mounts with dual lock Velcro (included). Easily removable. Powered by a lithium battery. ) I was thinking that there might be another way around the block for us Laser sailors: drill a hole in the bottom of a centerboard and mount a traditional boat speed indicator in it. The idea being you have a practice centerboard that includes the indicator and another one for other times. Here are my pros/cons: -No adhesive to apply/remove on a continual basis. -Easy to swap without pulling the boat out of the water. -Requires an extra centerboard. -Requires a possibly very narrow boat speed indicator. -Can one get a good reading from the bottom of the centerboard, or is the hull a better place? Any thoughts?