8 Winter Boat Storage Tips

Here are eight essential end-of-season tasks for boat owners to tackle before the snow flies or the rig faces long-term storage:

1. Fill or Drain

Fill your boat’s fuel tank(s) to near capacity with fresh fuel, allowing a little bit of room for expansion, and add stabilizer. Failing to do so will allow the air in the tank to condense on the sides as the temperature changes, adding water with the remaining fuel, which can cause corrosion and fuel contamination issues.

Turn off any fuel valves on the boat, and use duct tape to seal off any through-hull exhaust ports, which will also help prevent potentially harmful internal condensation. Another option is running/pumping all the fuel out of the tank before putting it into storage, the thought being that refilling the tank with fresh fuel before the next use will dilute any water buildup from condensation.

Burning Excess Fuel From Boat

Drain portable fuel tanks at the end of the season. Many boaters put the unused regular gas into their vehicle, mixing it with plenty of fresh fuel and report no adverse effects (avoid doing this if you have a two-stroke engine with pre-mixed gas, although same boaters claim doing is unlikely to negatively affect your car’s performance). Photo: Dan Armitage.

2. Protect the Engine Internally

Oil settles on the bottom of the block when an engine is not being operated for extended periods, exposing the pistons and valves to air, humidity and other corrosive materials. To guard against this situation, remove the spark plugs, spray fogging oil inside the carburetor and down the spark plug holes, and replace the plugs without reconnecting the wires. This task will provide a long-lasting protective coating for these essential engine parts and make things easier to start in the spring.

It’s also important to replace your engine’s old gear lube with fresh oil, and doing so now will make it quicker to get back on the water next spring. Exchanging old lube for new will eliminate water from the system and provide better overall protection for key internal parts. Also replace oil filters on inboard and outdrive engines. Dispose of any used oil at an authorized recycling center.

Boat Engine Maintenance

Boat engines need post-season care too, which should include fogging the cylinders, draining and replacing the lower unit fluid and a good visual inspection under the cowling. Photo: Dan Armitage.

3. Add Antifreeze

If your boat’s engine uses coolant, drain the existing fluid from the engine block and manifolds and replace with a non-toxic, propylene glycol base antifreeze. Despite pressure from the EPA and other environmental organizations, many antifreeze products still feature an ethylene glycol base, which is known to release toxins into the water. Not only is the propylene glycol variety better for the environment, most manufacturers say this type of antifreeze is better for your engine as well.

4. Remove Batteries, Electronics and Safety Gear

Disconnect the battery and store it inside for easier maintenance and better protection against theft. Make sure it is fully charged prior to stowing it away, be sure to maintain the charge throughout the storage period – especially if it is to be stored in an area that can reach sub-freezing temperatures — and replenish the electrolyte levels as needed. It’s also wise to remove all marine electronics from the boat for the winter, and to store this equipment in a safe place at home. Doing so will help thwart theft and possible damage caused by shifts in temperature and humidity. The winterization ritual also presents a perfect opportunity to remove items like dock lines, floatation devices, flares, fire extinguishers from the boat for inspection and possible replacement.

Boat Battery System

Remove your deep-cycle marine battery and clean the terminals with baking soda for long-term storage in a heated environment. Quick disconnect systems, such as those available from Connect-Ease, make removing and installing batteries easer. Photo: Dan Armitage.

5. Check the Prop

When the boat is on the trailer or blocks for the winter, it’s a great time to check your boat’s propeller and hub. Your prop blades may have become bent or nicked over the course of the boating season, or fishing line may have wound around the hub, which can diminish overall performance. The hub may also be have sustained extensive wear and may even be close to being stripped. If damage has occurred, you should repair or replace the propeller and make any necessary repairs to the hub and seal. Again, doing it now means you won’t have to worry about these things come springtime, when prop repair shops are likely to be back-up with work from boaters who put off this process until the start of the season.

Boat Propeller Maintenance

Now’s the time to take a good look – and a careful feel – of your prop to check for bent or nicked blades or fishing line. Better to find and fix it now than next spring, when prop shops are backed up by boaters who didn’t tackle this task at the end of the season. Photo: Dan Armitage.

6. Clean It Up!

Before putting your boat to bed for the winter, be sure to give it a good cleaning inside and out. If you store your boat with dirt, scum, and algae on the exterior, they will be even harder to remove in the spring. Once the exterior of your boat is clean, apply wax to create a protective barrier against dirt and dust. To help keep your boat free of mildew, you may want to install a dehumidifier or use one of the odor/moisture absorbers offered by various manufacturers. Turn any cushions up on edge so that air can circulate around them, or better yet, remove them from the boat for storage in a climate controlled area. Also remember to clean any bilges and drain any existing water. Remove all drain plugs and put them in a place where they’ll be easy to find when you’re ready to bring your boat out of winter hibernation.

Boat Cleaning Tips

Give the boat a good cleaning and a coat of wax before putting it to bed for the winter. Even aluminum hulls benefit from the post-season pampering and will be easier to clean come spring. Photo: Dan Armitage.

7. Up on Blocks

If you store your boat on a trailer, it’s a good idea to put the boat and trailer up on blocks for winter to take the pressure off the tires. You may even want to remove the trailer tires to help discourage theft while the boat is in long-term storage. This is a good time to inspect the trailer tires for wear and tear and to grease the wheel bearings, replacing them if necessary.

8. It’s a Wrap

Whether you’ll be storing your boat outside, or inside a garage or structure, it should be covered. If it will be outdoors and exposed to elements, you’ll need a storage cover to protect the interior of the boat from the harsh winter environment. Even if your boat will be kept in dry storage, a cover of some kind is recommended to guard the interior against dirt, dust, pests and bird droppings.

For outdoor storage, shrink-wrapping or quality 8- to10-ounce cotton canvas boat cover is ideal. Make sure that the cover properly sized and fitted for your particular boat model. It should also be supported so water will run off the cover and not accumulate in pockets. If your boat will be kept in dry storage for the winter, the waterproof quality and strength of the cover will not be important factors. In this situation, the main concern is keeping dust and other particulate matter from gathering on your boat, so nearly any type of tarp or cover will get the job done. A fitted cover is preferred however, because it will also keep mice, rats and other undesirables from seeking refuge in your boat and damaging the interior.

If weather conditions will be extreme, you may want to consider shrink-wrapping your boat instead of using a standard cover. Properly installed, shrink wrap will not blow off and can withstand heavy loads of snow or rain. Shrink-wrapping can be a “D-I-Y” job, but it requires proper tools, materials and instructions. Complete shrink-wrap kits are available through your local boat dealer, who probably offers installation as well.