How do you winterize your boat? A lot depends on what kind of boat you have, how large it is, and whether you leave it in the water or not. Trailerable boats can be easily hauled out and stored on shore, often at the owner's home or in a storage yard so they are easily accessible for cleaning, maintenance, winterization, repairs, and upgrades. It also keeps them safe from theft or damage at the marina.
Many aspects of winterizing a boat are similar to winterizing and RV. First of all, drain or freeze-proof all water systems (fresh water tanks, lines, and fixtures, waste water lines and tanks, and engine cooling systems). Remove all perishable foods, sundries, and supplies. Inspect all hatches and thru-hull fittings to ensure they won't leak.
If you have a trailerable boat, or have your boat hauled out for the winter, you may want to shrink wrap it to protect it from the elements over the winter. Doing it yourself can be a lot of work but there are companies that perform this service and are well worth it if it is within your budget. Covering your boat with a tarp will provide some level of protection, but it won't be as secure as shrink wrap and wind may wear holes in the tarp and/or damage the finish on the boat where it contacts hard surface. Custom fit boat covers provide a safer, more secure way of covering your boat but they can take time and can be quite expensive. We use a tarp over a PVC pipe frame to protect our sailboat. The tarp protects it from the weather; the pipe frame protects the boat from the tarp and allows access for off season work. When all assembled it looks like the boat is in a covered wagon!
While you have your boat out of the water is a good time to clean and inspect it. Hulls often collect algae, mollusks, and other unwanted growths that can inhibit performance and, quite frankly, look like crap! It would be a very good idea to thoroughly clean your boat, top and bottom, inside and out, before you put it into storage. Carefully inspect the deck and hull to determine if they need painting or other maintenance before you put the boat back into service next year.
If you leave your boat in the water you will want to ensure it is securely tied up so winter storms don't toss it around and cause damage. You will want to winterize all plumbing systems and remove perishable provisions and things that might be damaged by freezing if you are where it freezes. You may want to cover your boat with a boat cover or tarp for extra protection. If you do, make sure it fits well and is securely fastened. You should plan on inspecting your boat regularly so you can take care of any problems that come up such as loose docking lines or accumulation of excess water in pools on covers or tarps. Depending on how secure the marina is, you may also need to check for possible theft or vandalism while your boat was unattended. Thieves and vandals are usually quick to notice and take advantage when any property is left alone for longer than normal periods of time.
You will want to remove all perishable provisions and anything that might be subject to freezing. You may also want to inspect galley items to ensure they are clean before putting your boat into storage lest they attract pest during the winter. Clean tables, counters, and cushions and wash any bedding, linens and clothing you plan to leave in the boat before putting it into storage. Add used dryer cloths or moth balls to drawers and closets help keep bugs at bay. Used dryer cloths can be left between the sheets or in sleeping bags to help keep the beds fresh and clean.
Install some kind of device to reduce humidity when you put your boat into storage. If your boat is stored where you have access to 120 volt power there are electric de-humidifiers that will dry the air. For other situations you can get moisture control canisters that use chemicals to draw the moisture out of the air. I use them in my motorhome, motorcycle trailer, and my boat. I usually purchase them at Dollar Tree so they are not terribly expensive. They are small so they fit just about anywhere but the size does limit there capacity so you may need to swap them out several times during the winter for best results. Reducing humidity will help prevent mildew.
While your boat is out of commission for the winter is a good time to perform any need repairs, do regular maintenance, and work on any upgrades or enhancements you have been planning. It will be harder if you leave your boat in the water or have it shrink wrapped. Check the hull to see if the bottom needs painting. They often do after a season in the water. If you have anything you need or want to do this winter you may want to do it before you shrink wrap it if that is your plan for protecting the boat. Otherwise you may have to wait until you unwrap it next spring to get the job done. Making repairs as soon as possible is the best way to reduce further damage and minimize the chances of forgetting what needs to be done. In the paragraph below I describe the framed cover we use for our sailboat which gives us access to work on the boat just about all winter along.
We have a trailerable Macgregor 25 sailboat. Each winter we pull it out of the lake and bring it home. This saves several months of mooring fees, avoids risking damage from being banged around the docks by winter storms or icing, and keeps the boat in our yard where we can keep an eye on it. We built a shelter for our boat using a PVC pipe frame and a large, green farm tarp. The PVC bends enough to form bows over the boat to hold the tarp up, preventing possible damage to the tarp and the finish on the boat and allowing us access to the deck and the cabin for inspection and maintenance. It looks like a big green covered wagon over the boat. We drive 3/8" rebar into the ground as anchor points for each of the PVC pipes supporting the frame. We used 1/2" schedule 40 PVC pipe. For our 25' boat we use three horizontal pipes -- one at the ridgeline and one alongside each lifeline. We use 4-way (cross) connectors every 2' to run bows and legs from the ground on one side up over the boat to the ground on the other side. Then pull the tarp over and tie it down securely with bungie cords. You might want to glue the framework together or secure each joint with cotter pins or bolts, but I just use a press fit so I can easily replace any parts that may get damaged from snow loading and can disassemble it when it is time to launch the boat. Our original green farm tarp lasted through 5 years of rainy and snowy Oregon winters, including an unusually heavy snowstorm and strong winds in at least 2 seasons! This type of framed cover allows us to get into the boat for regular inspections and any maintenance, repairs up upgrades we need or want to do over the winter. You will need to monitor throughout the winter to make sure the tarp stays taught and doesn't collapse under the weight of snow or rain. Try to dump any puddles as soon as possible to minimize the buildup of weight on the protective structure. If it collapses on your boat it could cause expensive damage.
To minimize tear down and set up time we keep as much of the framework intact when we remove it each summer. If you glue it together be sure to leave enough room on each side to pull the whole boat and trailer assembly out and put it back in next season. If you choose to glue it together and use it as a semi-permanent structure you might want to consider using larger PVC pipe. We went with 1/2" pipe for flexibility and ease of handling as well as lower cost. We managed to break down our framework into about 6 pieces this last time and it took us less than 2 hours from start to finish to install the cover this year. The "covered wagon" style cover also allows us easy access to the boat for inspection, repairs, cleaning, maintenance, and upgrades over the winter while providing good protection from the elements. I find it handy to keep a supply of PVC fittings to replace any that get damaged by wind or snow loads (or I break taking it apart!). They should include Ts, elbows, and 4-way "cross" fittings.
We kept our original 1970 Macgregor Venture 24 sailboat after it was totaled by the insurance company when it fell off the trailer on the way to the lake last summer. It makes a fun playhouse for the grandkids and one day, with luck, we might find a new swing keel and mast to repair it and make it seaworthy again. We covered it with a tarp to protect it against winter weather and keep soggy leaves from staining the deck. I used sections of the broken mast to make a ridgepole down the centerl ine so that rain mostly runs off. Fortunately the tarp doesn't really contact any painted or gelcoat surfaces that might be damaged by chaffing, but it is already wearing through where it contacts the tops of the stanchions along the lifeline. Next year I should probably top each stanchion with a tennis ball.
The more you protect your boat for the winter, the less work you will face before launching it again next spring and the less chance there is of unwanted visitors making nasty nests or messes in or on your boat. Wet leaves can leave nasty stains on the deck so protecting it with some kind of cover will save you a lot of scrubbing (or repainting!).
Keep it protected!