[header] How to winterize a jet ski [title] Remove your jet ski from the water. [step] When you're done with the last ride of the season, get your jet ski out of the water as soon as possible. With your trailer securely attached to the back of your vehicle, slowly back your vehicle down the ramp until most of the trailer is underwater. 
Then get onto your jet ski, drive it up onto the trailer, and hook it to the trailer. Get back into your vehicle and slowly drive forward to safely remove the jet ski from the water.