On-board instruments present modern sailors with a wealth of information. There's apparent and true wind speed, boat speed, speed over the ground and velocity made good - to name just a few. But what do the numbers really mean and how do you use them to win races? Sail Smart answers these questions and turns on-board information into racing results, Mark Chisnell gives an expert guide to how to turn the theory into practice to ensure you stay ahead of the fleet. By mastering your instruments you can make the right calls every time and how for certain when to tack, which shift to look out for and how the tide can work with or against you. With colour diagrams throughout, this instructional guide turns information into excellence. Sail Smart is accessible to those new to racing, yet has a depth of information that will transform the performance of even professional sailors. Cruising sailors will also benefit from understanding how to get the most from their instruments. The information is at your fingertip - now turn that knowledge into racing success.