N.A.D.A. Snowmobile/Motorcycle/ATV/Personal Watercraft Appraisal Guide. New editions are available for purchase (Jan. - May - Sept.) If determining current values for used snowmobiles, motorcycles, ATV s or personal watercraft is part of your business, then you need the best appraisal guide available. Whether you re buying or selling, N.A.D.A. has the information you want. It s complete, up-to-date, and easy to use.