Boat Winterization Guide

As the cold season sets in and the boating season wraps up, it's time to winterize your boat. Winterization is critical for boaters as it prepares your watercraft for the long idle months and the rigors of freezing weather, ensuring it remains in excellent condition and ready for the next boating season.

Boat winterization can be tedious but not complex. While you may bring in an expert to winterize your boat, it's also something you can do yourself. With step-by-step guidance, winterizing your boat can be fast and easy.

Why Should You Winterize Your Boat?

Whether you dock your boat, keep it onshore or store it indoors during winter, you should winterize it to avoid damage from freezing temperatures. Once temperatures drop below zero, unwinterized vessels can suffer damage, especially if they have water inside key components like the engine. Water expands when it freezes due to molecules bonding further apart, unlike in the liquid state. Such an expansion could cause severe damage to critical parts.

Winterization leaves your boat clean, drained and dry, preventing numerous harms. Here are some of the benefits of properly winterizing your boat:

• Engine protection: Winterization removes water from the engine, which could freeze, expand and damage internal parts.
• Battery maintenance: Removing, cleaning and storing batteries protects them from damage and power drainage due to freezing temperatures.
• Corrosion prevention: Ensuring the inside of your boat is clean and protected from moisture prevents corrosion.
• Mold prevention: Winterization eliminates moisture, which can cause mold and mildew to grow.
• Fuel system protection: Filling up the fuel tank and adding a high-quality marine stabilizer prevents fuel breakdown and corrosion from occurring in the fuel system.

• Hull protection: Winters can be harsh. Proper boat care prevents snow, storms and cold temperatures from damaging the hull and deck.

Your boat is a large investment that relies on preventive maintenance to remain in good condition. Sticking to a simple winterization routine will help you avoid preventable issues that could lead to costly repairs.

How Long Does It Take to Winterize a Boat?

If you're considering DIY winterization, it's wise to know how long the process takes so you can prepare accordingly. Various factors impact the duration of winterization, such as your experience, the size of your boat and the engine type. Smaller vessels take less time to prep than larger ones due to the size and complexity of the systems. Also, since outboard motors have a simple design, they are easier to winterize than inboard ones.

Here's a breakdown of how long it takes on average to winterize various boats:

• Small vessels: Small boats and personal watercraft (PWC) have simple designs with accessible parts. As such, they can take one or two hours to inspect, clean and prepare for storage.
• Sailboats: Due to the complex parts such as rigging, masts and sails, sailboats need more time and attention and may take up to six hours to winterize.
• Cabin cruisers: Larger boats like cabin cruisers and yachts will take more time to inspect, flush, drain and care for key components. Due to the complexity of their systems and designs, they can take anywhere from four hours to a day.

Essential Winterizing Tools and Products

As you prepare to winterize your boat, you'll need to gather the necessary supplies to ensure a fast and uninterrupted process. Some of these products are also vital to keeping your boat safe during the off-season. Here's a breakdown of tools and products you may need:

• Cleaning and waxing kit: A basic cleaning kit should include a scrub brush, a sponge, a bucket, and a bottle of wash and wax soap concentrate. You probably have some of these items around the house, or you could buy a pre-packaged kit. Alternatively, you can use ordinary soap to clean and a specialized marine wax to polish the surfaces.
• Antifreeze: To ensure effectiveness, you'll need proper antifreeze rated below your expected freezing temperatures. Choose a nontoxic propylene glycol antifreeze that is safe for marine environments.
• Marine fuel stabilizer: A fuel stabilizer is an essential product that prevents fuel degradation in the fuel tank. You'll need a stabilizer that's specific for marine use.
• Motor flush kit: An engine flush kit is optional, as you can flush your engine with fresh water. However, the product is designed to remove salt, sediments and other contaminants that plain water may fail to wash out.
• Marine lubricant: Lubrication is crucial for preventing corrosion in moving parts. Select marine-based lubricants designed for the unique environment.
• Trickle charger: Since your battery will be stored for a long time, you may want to use a trickle charger to charge it at a low voltage. A trickle charger keeps your battery active and fully charged and prevents damage while in storage.
• Boat cover: A high-grade boat cover is a must-have when winterizing your boat, even if you're storing it indoors. If you store it outside, a well-fitting cover will protect the interior and exterior from the brunt of winter. Remember, a high-quality tested boat cover is more effective than an ordinary tarp.

Step-By-Step Guide to Winterizing a Boat

Your boat's various systems have different demands during winterization. Our step-by-step process addresses the various sections of your boat.

The Engine

The key to winterizing your engine is ensuring there's no water left in the system since water causes the most damage when temperatures drop below freezing. Draining engines need to be thorough, so pay attention to the engine type and the manufacturer's manual, as some engines have unique instructions.

Outboard engines can drain if left tilted for a while. If you have a modern engine with a self-winterization mode, follow the manual. In general, winterizing your outboard engine requires these steps:

1. Wash the engine with soap and water and flush it.
2. Run the engine with the fuel line disconnected until it stops.
3. Lubricate the exterior and cylinders with fogging oil.

Due to varying inboard engines with stern drives or direct drives, refer to your manual for specific directions. Still, these engines must also be flushed and fogged, and the oil needs to be changed.

For engines that need oil and filter changes, run the engine to allow it to pick up impurities, then change the oil and replace the filter. An oil change kit could be worth having on hand.

Water Drainage System

This step is not applicable if you own a PWC or a small boat not designed for overnight stays, this step is not applicable. For larger boats and yachts with plumbing systems, you must drain the tanks, faucets and heads by running the water until the freshwater tank is empty. Run nontoxic propylene glycol antifreeze through onboard plumbing to prevent damage to the pipes. The only way to be sure all the piping contains antifreeze and not water is to open the faucets to see if the antifreeze flows through.

For the marine sanitation system, follow these steps to ensure proper winterization:

• Dispose of the waste at an approved facility. It is illegal to dump human waste in water bodies unless you're more than 3 miles offshore.
• Wash the holding tank, allow it to dry, and apply antifreeze.
• Inspect the hoses for signs of wear and damage. If the discharge and intake pipes are fine, circulate antifreeze through them.
• Lubricate seacocks and gaskets.

Fuel System

The fuel system is an extension of the engine, and proper care leads to optimal engine performance come spring. Start by inspecting for leaks when the engine is running, then replace the fuel filter canister and fuel separators. You can drain out the remaining fuel or fill up the tank. Draining out the fuel is the safest option as it prevents issues like moisture absorption, freezing and phase separation in the case of ethanol-blend fuel.

Alternatively, you can keep the fuel and stabilize the fuel system. Fill the fuel tank to capacity to avoid condensation buildup, and add a quality marine-safe stabilizer to prevent the fuel from breaking down over the winter. Run the engine briefly to circulate the stabilized fuel through the system.

Interior

Your boat's interior condition after the offseason depends on initial care. Like the working components, the interior is vulnerable to the harsh winter elements. Winterizing the inside of your boat starts with cleaning, waxing and leaving compartments open to discourage mold buildup. Here is a quick checklist for boat interior:

• Clean and dry surfaces using moisture-absorbing products.
• Remove curtains and cushions and store fabrics off the boat.
• Clean and dry storage compartments. You could apply a marine mold and mildew inhibitor to discourage fungal growth.
• Clean out the refrigerator and freezer.

Interior surfaces and materials matter when cleaning. Follow the best practices for cleaning a boat's interior for step-by-step guidance on what to do and what to avoid.

Bilge System

Water collects in the bilge as you use your boat, making it necessary to drain and clean the bilge system. In small boats, empty the bilge by removing the bilge plug and letting the water drain out. For larger boats with a bilge pump, inspect the pump and clear any debris around the area before switching it on. Drain the water, clean the bilge, and leave it to dry. You may spray the area with a moisture-displacing lubricant.

If draining all the water is challenging, add antifreeze to keep the remaining water from freezing when temperatures drop. For a boat that docks throughout the winter, clear debris to avoid the risk of a clogged pickup or interference with the switch. Wire the pump to the battery so it can still operate when all systems are off.

In addition, remember to leave the bilge pump switch in the "auto" setting. These preparations will help safeguard your boat if water collects in the bilge.

Hull and Exterior

Your boat's hull and exterior surfaces need cleaning to remove dirt, salt and marine growth. Applying a coat of wax will help protect the hull from the elements. If your boat will remain in the water for the winter, consider using an antifouling agent to the areas below the waterline to prevent barnacles and other marine growth.

A boat stored outdoors should be covered due to freezing temperatures and rough weather. You should also cover the boat if you're storing it indoors and aren't certain the shed or garage can provide adequate protection from freezing temperatures. Various boat cover options exist. Inexpensive solutions like nylon, canvas and polyethylene tarps can withstand winter elements but are likely to blow off without proper fastening and are better suited for indoor storage.

For outdoor storage, consider professional shrink-wrapping. It's a one-time job that offers a perfect fit and provides superior protection for your boat's exterior.

The Battery

For boats that stay offshore, remove the battery, charge it to capacity, and store it in a dry place where temperatures won't fall below freezing. You could use a trickle charger to maintain the charge level. If you keep the battery aboard, especially when storing the boat in the water, here are tips to keep it healthy and operational:

• Fill a wet-cell battery with electrolyte.
• Clean the connections with a pot scrubber, and coat them with a corrosion inhibitor to prevent corrosion.
• Hook the battery to a marine smart charger instead of a trickle charger. Smart chargers deliver voltage based on battery chemistry and acceptable limits.
• Occasionally, check and recharge the battery if you leave it unplugged.

Storage

Proper storage is critical to winterizing your boat because it ensures the vessel gets through the winter without issues. There are two ways to store your boat — in-water or offshore. Additionally, offshore storage can be indoors or outdoors. When storing your boat in the water, you have several factors to consider to ensure proper winterization, such as the surrounding water getting in, ice damage or snow buildup submerging vital areas like thru-hulls.

Here are areas to address when storing in the water:

• Close all thru-hulls and below the waterline openings.
• Remove drain plugs to prevent freezing damage or replace them with one-way types if there's a threat of storms.
• Plug the exhaust ports to prevent water entry and pests.
• Keep the float switch working and free of obstruction.

For offshore storage, you must consider the support system to prevent hull damage. Here are several solutions for supporting your boat offshore:

• Custom-made cradles: These are designed to hold your specific boat model, providing adequate support to critical areas.
• Trailers: Trailers are adjustable and reliable, with the advantage of being mobile.
• Jackstands: While not ideal, jackstands can do the job when strategically placed with proper weight distribution.

Shop Winterization Products at Fawcett Boat Supplies

Winterization is an essential part of boat maintenance that protects your vessel during the harsh off-season months. Our step-by-step guide addresses different areas of your boat that need care and offers recommendations for winterizing products to streamline the process. Since securing your boat for the cold months relies on proper tools and products, quality matters.

As a leading marine supplies store, Fawcett Boat Supplies is committed to providing customers with high-quality supplies, from boats and motors to sailing hardware and safety gear. We have a team of experts with decades of boating supplies expertise at your service. Browse our online winterization collection, and contact us with any questions!