A One-Design Keelboat is a type of sailing vessel designed to be identical in construction and performance. This ensures that all boats in a class are equal, allowing for fair competition among sailors. The design focuses on uniformity in dimensions, weight, and sail area, which helps to emphasize the skill of the crew rather than differences in the boats. These keelboats are often used in racing events and are popular in sailing clubs. Examples of one-design classes include the J/24 and Sonar. The concept promotes a level playing field, making it accessible for both amateur and professional sailors to compete.