How to winterize a sailboat in 9 Steps

Winter is coming and it’s time for winter storage for your boat! Sailing for some of sailors is not a year-round event and therefore, the need to appropriately store and winterize your sailboat is crucial. Learning how to winterize a sailboat is a crucial skillset for a sailor.

how to winterize a sailboat

Here, World Sailing Charters provides you with a guide on how to exactly winterize a sailboat in 9 simple steps. Before you start however, please be sure to FIRST: check your sailboat’s owner’s manual for any sailboat-specific winterizing instructions or needs.

Winterize a Sailboat 10 Steps:

  1. Draining Fluids
  2. Batteries
  3. Additional Equipment & Supplies
  4. Cleaning
  5. Inspection & Repairs
  6. Sails
  7. Cabin
  8. Covering
  9. Storage

What does winterization mean for your sailboat?

Traditionally, winterization takes place when complex devices or objects such as a car, electronic or radio, boat, and other systems are not built to operate at low temperatures.

Winterizing by definition then, means that a sailboat may have to undergo treatments, additional waterproofing/insulation, or even total substitution and replacements for new parts for the winter season.

Step 1: Draining Fluids From the Boat

Draining fluids from your sailboat involves a few different types. These are:

  1. Fresh Water
  2. Fuel

In order to begin winterizing your sailboat, you need to drain all of the fresh water from within it. Once that is done, and you are sure that the system has been completely drained, we recommend cleaning out all o the tanks. With a water system figured out and drained, it’s time for antifreeze. Take care to get rid of any build-up. Then, re-fill the system with antifreeze.

Raw water on your boat

Raw water on a boat refers to the water that the boat is floating in. And if you’re thinking ‘what is the difference?’ and actually, there is no raw water difference between salt of fresh. Both types are used to cool the engine.

It’s important to note that when buying antifreeze for the winterization process, you purchase an antifreeze that you can mix with a 1:1 with water PRIOR to adding it to the system. At this stage, make sure that each and every pump or hose in your fresh water system is filled with antifreeze mixture.

Two considerations for fuel draining:

If your sailboat has a gasoline engine, the only step to take here is to drain all of the fuel out of the engine and make sure you leave the tank empty. If you have a diesel engine, the step to take is to supplement the fuel tank with a stabilizer.

Once added to the fuel tank, top-off the tank with some fresh diesel. Then, replace all of the fuel filters on the sailboat, drain the water separator until it’s completely dried, and run the engine for about 20 minutes.

What is a diesel engine?

The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to the mechanical compression; thus, the diesel engine is a so-called compression-ignition engine.

Step 2: Removing Batteries from the boat

As one of the most important steps in sailboat winterization, removal of batteries takes place. This step doesn’t end here however, you will need to continue charging maintenance on the batteries about once every thirties days throughout the winter.

Generally speaking, when it comes to batteries, boat owners will have a bank of main batteries, as well as a starter battery.

Here are the most common types of batteries you may encounter:

  • Lead-acid (The lead–acid battery was invented in 1859 by French physicist Gaston Planté and is the earliest type of rechargeable battery.)
  • AGM (First developed in the 1970s, AGM batteries use glass fibers woven into very fine a mat which is saturated in sulfuric acid)
  • Gel (A gel battery design is typically a modification of the standard lead-acid automotive or marine battery. A gelling agent is added to the electrolyte to reduce movement inside the battery case)
  • Lithium (LiFePo4) (LiFePO4 batteries are the safest lithium battery type currently available on the market today. The nominal voltage of a LiFePO4 cell is 3.2V when comparing to sealed lead acid, which consists of 2V cells.)

Your owner’s manual should help specify the cycles needed for your battery types. At this stage, if you have any extra electronics onboard, take care of those and bring them inside for safe storage. Winter can do damage on electrical lines and in order to winterize appropriately, take care to sweep your boat for any damages to them.

Step 3: Removing Additional Supplies

As a general rule of thumb for preparing a sailboat for winter (or any boat for that matter!) leave less on the sailboat if you can help it. You want to avoid damage or even theft of anything on it. At this stage, take care to ensure that all safety equipment is up to code. This means checking your sailboat’s:

  • Personal Flotation Device
  • Fire Extinguishers
  • Flares
  • Lines or Water Lines (Coiling the line (rope) and storing it on the boat railings or inside a bag or a bucket is one of the easiest and efficient ways to store the boat lines. However, while storing them outside, you need to keep them away from the sunlight because sunlight can cause any damage to the lines.). During the winterization process, you should store your lines indoors and away from any potential animals that will chew on them.
  • Lights

Always, always make sure – you check the expiration dates on every safety equipment on-board your sailboat. This is not only the safest thing to do but also ensures that everything is operational.

Step 4: Cleaning Your Boat Carefully

As you winterize your boat, you’ll quickly realize how messy or dirty certain parts of it can be. After the additional supplies are removed, you’ll have more space to inspect the boat for areas that need cleaning attention. Take care to tackle dirt, any grime, mold, and stains. Not only is a clean boat much more enjoyable but it allows for it to last longer, for more seasons.

Here are some of the best cleaning products for your boat:

  • Star Brite EZ-On EZ-Off Hull Cleaner
  • Meguiar’s M43 Boat Wash
  • Boat Juice Exterior Cleaner

Pro boat cleaning tip: Some boats are carpeted inside from bow to stern. The best way to clean it is to first use a vacuum to remove loose dirt, followed by scrubbing down, and finish with a stiff-bristle brush, soap, and water.

Step 5: Inspecting Your Sailboat For Possible Repairs

Now that the boat is drained, mostly emptied, batteries are removed, and you had a chance to clean, you can and should inspect for possible repairs or replacements for the next sailing season. Water damage can be sneaky and extensive.

What does water damage look like?

Stains and mold are signs of water damage. Stains often develop if there is a slow, consistent leak, while mold will appear if areas are consistently damp. Most water stains are a yellowish-brown color and typically expand in irregular shapes from the source of the water leak.

Sometimes when we notice damage to our boat parts, it’s too late for an intervention and replacing entire areas is needed.

Check for signs of corrosion, rust, and mold. Any water lines that need attention should be inspected at this point. Service all seacocks, winches, turning blocks, rope clutches, and the mainsheet.

Step 6: Paying Attention to Your Sails

Ever wonder what sails are made of? At this stage, you’ll become fairly acquainted with what sailcloth your boat has. It’s important to clean the sails before storing them for the winter but be mindful of how much cleaning you actual do to them!


Different types of sailcloth materials:

  • Aramid-Kevlar Fiber
  • Carbon Fiber
  • Dyneema Fiber
  • Nylon Fiber
  • Polyester Fiber
  • Technora Black Fiber
  • Vectran Fiber
  • Woven Polyester Fabric (Dacron)

It’s important to note: Excess cleaning can actually harm sailcloth so what you should do instead is lightly spray them down and wipe off any damp areas. Check for any holes and patchwork that needs to be taken care of. Use this time off from sailing to fix rips and tears in the sails.

At this stage, you should inspect the sails for any damages and depending on what material the sails are made of, you should allow for them to dry indoors, away from sunlight.

Pro Tip when winter prepping your boat sails:

Store the sails away from possible mice and/or rodents! They absolutely love burrowing and damaging sail material during the cold months. Make sure you elevate the sails for storage, away from potential intruders.

Step 7: Organizing & Rearranging Your Boat Cabin

Depending on what type of cabin your boat has, different steps for winter will need to be taken. For starters, if you have a stove or other appliances, make sure they are all turned to the “off” position. Any food or left over beverages from your trips should be removed and not left over. Remember, mice love to make boats their homes in the winter months. Do not fall victim to them!

If the cabin has cushions that can be easily removed, take care to store them away for the winter as well. Some material in the cushions are washing machine safe and as always, consult your boat owner’s manual for them.

Step 8: Covering Your Boat Options

You have two options when it comes to covering your boat and they all depend on Step 9, deciding the appropriate storage for your boat. You can use a trailering cover for the boat or consider shrink-wrapping instead.

The bottom line: make sure you use anti-chafing material and that the covering is snug tight like a sailing glove around the boat. This again, prevents animals from getting in and making a home during the winter months.

You can always spring for custom-fitted shrink wrap here and we think it works as your best option. Why risk damaging the boat when it’s not in use, right?

Step 9: Appropriate Storage Options for Your Sailboat

Storing your boat comes in two different options with sub-categories for each. Basically, if you are going to store your boat outdoors, make sure you follow our 9 steps and consult with your owner’s manual before doing so. Storing a boat outside is not unheard of and depending where you live (what climate you’re expecting) this may be the best option.

winterize a sailboat

If you choose to go with an outdoor facility, you will want to go for a heavy-duty cover for your boat. This is because your boat will be outside and exposed to the elements.

Indoor storage of boats is also a viable option that many of us go for. The advantages of an indoor boat storage facility is maximum coverage and protection.

This option may be more expensive but when you compare it to potentially having to fix your boat due to winter damages, it tends to pay off. Check for local boatyards and boat storage facilities that specialize in the winterizing process and you should come out just fine in time for spring!

Your boat is ready for winter

Now that you took time to follow our 9 steps on winterizing your boat, it’s important to get ready for next spring. The process of de-winterizing a boat comes with specific steps as well. Some boat owners (newer ones, at least) are surprised to find this out! You just successfully prepared your boat for the chilliest season – congratulations!

Have more steps for us to mention? Feel free to contact us and let us know what steps you think are the most important or even missing in our simple guide!

Recent Posts