For a sailboat point of sail affects lateral force significantly The higher the boat points to the wind under sail the stronger the lateral force which requires resistance from keel or other underwater foils including daggerboard centerboard skeg and rudder Lateral force also induces heeling in a sailboat which requires resistance by weight of ballast from the crew or the boat itself and by the shape of the boat especially with a catamaran As the boat points off the wind lateral force and the forces required to resist it become less important On ice boats lateral forces are countered by the lateral resistance of the blades on ice and their distance apart which generally prevents heeling Forces on sailing craft Aerodynamic forces in balance with hydrodynamic forces on a close hauled sailboat Text Drive vs drag on sail Text Forward resistance vs lateral resistance Sailing craft with low forward resistance and high lateral resistance File Bladerider 8 jpg International Moth class sailboat on foils File Iceboat2 jpg DN class ice boat File LandYacht jpg Land sailing craft