This paper presents a straightforward momentum-transport model for sailing, specifically focusing on sailboats and their interactions with air and water. The model simplifies sailboat physics by assuming that the boat is powered by the relative velocity of the air and water, adhering to Galilean relativity. The primary focus is on sailboats’ ram-pressure forces, which are responsible for redirecting fluid momentum. This simple model is Galilean-relativistic and dimensionally correct, making it easy to implement and ideal for understanding the fundamental physics of sailing. The model demonstrates that sailboats can achieve impressive dynamics, travel faster than the wind, and navigate upwind and downwind through tacking. Additionally, the paper discusses optimal sailboat settings and offers insights into potential applications, including the physics of sailboat and ice boat design. This model simplifies the complexities of fluid dynamics and is designed to provide a basic understanding of the fundamental physics behind sailboats.