How do you winterize a 800 cc Yamaha waverunner?

To winterize an 800 cc Yamaha Waverunner, start by flushing the engine with fresh water to remove salt and debris. Then, change the oil and oil filter, and add fuel stabilizer to a full tank of gas to prevent condensation and fuel degradation. Remove the battery, clean it, and store it in a cool, dry place. Finally, cover the Waverunner with a breathable cover to protect it from dust and moisture during the winter months.