When you buy a boat, new or used, there generally isn't ONE all-inclusive manual. There will be several booklets, one for the boat, one for the motor, one for the trailer. They are all made by seperate manufacturers. In addition, if you are lucky, there will be paperwork on boat systems such as radio, steering, controls, canvas & vinyl. My Godfrey dealer had all of that for me in a nice canvas bag, as the boat was new. It may be easier to research on the internet, or contact specific manufacturers. If you do post on here, please list the brand names, sizes, and hp.
18 ft. Sweetwater Sunrise (F) Pontoon "Slice of Life" ; 40hp. Yamaha