Putting your boat in storage for the winter is the best way to ensure it's still in good, usable shape come spring. But before you put the boat in storage, there are some preparatory tasks you need to take care of. The best way to remember these four main tasks is with the anagram BEEC.
Charge your boat's battery, if it is not fully charged already. This way, when you want to take the boat out in the spring, the battery will already be ready to do. After the battery is charged, unhook the terminals. Start with the negative one for safety reasons! If there is any battery acid on the battery terminals, you can use a weak solution of baking soda and water to clean it off. Wear gloves to protect your hands from the battery acid.
Prepping the engine is, perhaps, the most extensive and important part of prepping your boat for storage. Flush the outboard engine according to instructions in your boat's owners' manual. Then, disconnect the fuel hose from the engine, and drain any fuel into a pan. Turn the boat on to burn any residual fuel in the engine. Then, move onto the gear case, using a soap and water mixture to wipe it down and remove any residue. If you also have jet drive motors, pump the water out of them, and then change all of the oil.
You don't have to really prepare the electrical systems, so much as check them over to ensure everything is working. It's not uncommon for rodents to cause damage to electrical systems while in storage. When this happens, the storage company or your insurance company might pay for the damage, but only if you can prove it happened in storage. Test all of your electrical components now so you have a baseline for comparison when you pull the boat out of storage later on.
Now that the boat's inner workings are all ready for storage, it's time to focus on the cosmetics. Remove all trash and food items from the interior of the boat. Give any cloth surfaces a good wipe-down with an anti-mildew cleaner, and if you see rust on any metal surfaces, scrub it away before applying a coat of Rustoleum. If there are any barnacles on your boat's hull or plant life stuck in the rudder, scrub the debris away and apply a solid coat of wax to the exterior of the boat.
If you remember the acronym BEEC, you'll go a great job of prepping your boat for boat storage this winter.