Wakeboard length is primarily determined by rider weight, because weight affects how the board sits on the water. A board that is too short may feel unstable and sink too much, while a board that is too long can feel slow and difficult to control. Manufacturers provide size charts that match rider weight ranges to board lengths, making selection easier. Skill level also matters, as beginners often benefit from slightly longer boards for added stability. Choosing the correct length helps with easier starts, better balance, and smoother progression.