To protect your dog from sunburn while boating, apply a vet-recommended, unscented sunscreen, especially on exposed areas like the nose, ears, and any patches of thin or light-colored fur. Opt for pet-specific sunscreen to avoid any harmful ingredients. Additionally, provide shaded areas on the boat where your dog can retreat from direct sunlight. Consider lightweight, UV-protective clothing designed for dogs for extra protection. Regularly reapply sunscreen, especially after your dog goes swimming, to ensure continuous protection throughout your boating adventure.