What you'll need:
A Jet Ski on a trailer
Access to a Dock to load the Jet Ski into the water
A car or truck or something capable of towing the trailer (with and without the Jet Ski on it)
And, of course, a Life Jacket
Step 1: Personal Flotation Device
Grab a life jacket before getting on or even looking at the Jet Ski. The water doesn't care how good of a swimmer you are; under the deceptively pleasant surface of the water it is harboring a deep grudge against you for leaving it to walk on land.
Water will kill you. And it won't even send flowers to your funeral afterward.
So grab a life jacket, one of those ones that you can strap yourself into. Chances are if you get thrown from the Jet Ski you won't be in the proper state of mind to swim.
Water, she be a fickle mistress. Much like gravity.
Step 2: Equipment Check
Before doing anything with the Jet Ski you must check to make sure that you have the proper equipment on your Jet Ski. A small Fire Extinguisher should be located in an easy to find panel and you should always check that it is there before starting your Jet Ski. You wouldn't want to have your engine on fire when you are surrounded by water.
Make sure that the safety strap is attached to the kill switch on the Jet Ski. Most
Also check and make sure all of the straps, the one on the front that holds the Jet Ski on and any other additional straps, are secure and tight. You wouldn't want to lose the Jet Ski on the way to the water.
Step 3: Driving to the Dock
These seems like an obvious step but I'm putting it in here as a word of warning.
Drive there, don't try to walk it there.
The reason for this gets more obvious later.
Step 4: Backing Down the Ramp
This is where it pays off to have a vehicle. Though it may be a bit harder to steer it down the ramp than it would be if you were backing it down on foot it is much easier to stop. Also, if the water rejects your offering of the Jet Ski it is much easier to get away on a vehicle.
Back down the ramp slowly. Don't be afraid to brake. Have a buddy help direct you down the ramp. Stop before getting into the water.
Step 5: Perform a Dry Start
You don't want to get the Jet Ski wet if it won't even start, so make sure it does before you get in the water.
Don't get yourself caught dead in the water; you can never trust the water.
Step 6: Unhooking the Extra Straps
Take this moment outside of the water to unhook any extra straps you may have on the trailer at this time (that means the straps connecting the trailer to the Jet Ski and not the trailer to the vehicle).
Leave the front strap connected to the Jet Ski.
Step 7: Unhooking the Front Strap
Before you back the Jet Ski fully into the water unhook the front strap. Make sure you do this before backing all the way in; a floating Jet Ski will mess you up if you try to unhook it in the water. It may pull a knife. I'm not saying it will, but it is kind of shifty.
Step 8: Push the Jet Ski Off the Trailer
The title is pretty self explanatory. All you have to do is push the Jet Ski off the trailer. But don't just push it off and turn around, or the water will reclaim it. Hold on to it. You don't have to move the trailer out of the water just yet, but if you still have that buddy around it would hurt to move it. Just watch your toes.
If you have a Jet Ski that can reverse, skip this and the next step.
Step 9: Turn the Jet Ski Around
Unless you have a Jet Ski with reverse, you are going to need to turn the Jet Ski around before you start it. Otherwise you will end up running into land. In case you were wondering, that is a bad thing.
Step 10: Mount Her
Always get on from the back of the Jet Ski. Let's be honest here, you aren't that thin anymore, all those late night snacks are catching up with you. So approach it from the rear, otherwise you will end up flipping it and possibly kill yourself or damage the Jet Ski.
Step 11: Put on Your Saftey Kill Swiitch Strap
Don't forget this part. This will kill the engine in the event that you fall off. You'll want that, lest the water take away your precious Jet Ski.
Step 12: Start the Engine
Only after you have the strap on and are safely on the Jet Ski can you start the engine. And listen to that baby purr. Nice.
Step 13: Have Fun
Start her up and get to showing the water who is boss. Maybe take occasional breaks so your buddy can ride too. Or be selfish and ride all day. See if I care.