How to Protect Your Jet Ski During Long Periods of Non-Use: Complete Guide for Long-Term Storage

When the riding season ends and your jet ski (or any personal watercraft, PWC) is sitting idle for months, it’s tempting to just throw a cover over it and forget about it. But putting your jet ski into storage without proper preparation is one of the fastest ways to reduce its lifespan, invite corrosion, and rack up unnecessary repair costs.

Whether you’re dealing with winter, an off-season, or simply taking a break, this guide outlines how to protect your jet ski during periods of non-use—keeping it in great shape and ready for your next ride.

Why Jet Ski Storage Matters

Jet skis are built to handle water, but ironically, improper storage can cause serious water-related damage. Corrosion, rust, salt buildup, battery degradation, and dry rot are just a few risks of long-term neglect.

Protecting your ski during downtime doesn’t just save money, it extends the life of your investment and helps you avoid unexpected issues when you’re ready to hit the water again.

Step-by-Step: How to Protect Your Jet Ski During Long-Term Storage

Long-term storage can be tricky. Sometimes, owners make mistakes during off-season storage. This guide will help you avoid those mistakes and keep your jet ski in top shape for the next season. 

1. Clean Your Jet Ski Thoroughly

Before storing your PWC, completing a full wash and dry is essential. Salt, sand, dirt, and grime can wreak havoc on your ski’s hull, engine components, and trailer.

When cleaning your jet ski, you should:

• Use marine-safe soap and rinse the hull, seat, intake grate, and nozzle.
• Flush the engine using a garden hose to remove excess water, salt, and debris from the cooling system.
• Tilt the trailer slightly (toward the back) to help drain any remaining water from the exhaust system.
• Dry the ski completely to prevent mold, mildew, and corrosion. Pay special attention to the storage compartments, under the seat, and footwells.
• Use a low-pressure leaf blower or air compressor to blow water out of tight spots.

2. Apply Spray Fogging Oil to Prevent Rust

After cleaning and drying, spray fogging oil into the engine’s air intakes and spark plug cylinders. This creates a protective coating inside the engine and prevents internal corrosion.

Use a quality spray fogging oil product designed for marine engines. With the engine running, spray into the air intake until it begins to stall. Then remove spark plugs, spray fogging oil directly inside the cylinders, and turn the engine over a few times to distribute the oil evenly.

Fogging oil forms a barrier against rust, especially in high-humidity or off-season storage locations like garages or boatyards.

3. Use a Fuel Stabilizer and Fill the Tank

Fuel degrades over time, especially ethanol-blended gas, which attracts moisture. This can gum up the fuel system, clog injectors, and cause starting issues when it’s time to ride again.

You should:

• Add a high-quality fuel stabilizer (like STA-BIL or Yamaha Fuel Med RX).
• Run the engine for a few minutes to allow the stabilized fuel to circulate throughout the entire system.
• Fill the tank to reduce air space and prevent condensation inside the tank.

Leaving a partially full tank invites moisture, leading to corrosion in your fuel system and engine.

4. Battery Maintenance: Don’t Just Disconnect—Maintain

Simply disconnecting your battery is not enough. Batteries self-discharge over time, and if left too long, they may not recover.

When storing your jet ski, you should:

• Remove the battery completely and store it in a cool, dry location (not on concrete).
• Use a battery tender or smart charger to maintain a charge during long storage.
• Avoid overcharging—opt for a device with an auto shut-off feature.

A dead battery is one of the most common service calls in spring. Prevent it by taking care of your jet ski’s battery now.

5. Protect the Jet Ski’s Exterior and Trailer

Don’t ignore the outside of your ski. Sun, dust, water, and elements can cause serious wear to seats, plastics, and paint.

To protect your jet ski’s exterior, you can:

• Apply a marine-grade wax to the hull for added UV protection and to repel grime.
• Lubricate any metal components and moving parts, including throttle, steering, and linkages.
• Inspect and protect your trailer tires—inflate them to the correct PSI, and consider using tire covers to prevent dry rot and UV damage.

Storing your ski on a loading dock or trailer? Be sure it’s tilted slightly backward to aid drainage and prevent standing water in the hull.

6. Use a Proper Jet Ski Cover

A tight-fitting, breathable jet ski cover is one of the best ways to protect against dust, sun, rodents, and debris. Avoid cheap universal covers that may trap moisture.

Make sure the cover fits snugly and has ventilation to prevent mold growth. Also, secure all straps and check the cover after storms or wind.

If storing in a garage, you should still use a jet ski cover, as dust and moisture can still settle and cause damage.

7. Choose the Right Storage Location

Your storage location matters just as much as your prep routine. The goal is to avoid exposure to elements, fluctuating temperatures, and moisture.

For storage locations, consider the following:

• Ideal: Indoor storage in a climate-controlled garage or facility.
• Acceptable: Covered outdoor storage with strong UV and water protection.
• Avoid: Leaving your ski exposed on a beach, dock, or in uncovered yards.

If storing outdoors, elevate the ski slightly and hook up a tarp beneath the cover to keep ground moisture away.

8. Log Your Maintenance and Prep Steps

Keep a storage log detailing:

• Date of last fuel stabilizer use
• Battery condition
• Oil change (if performed)
• Steps completed
• Any signs of wear or cracks

This makes it easier to review and complete a pre-season checklist when it’s time to bring your jet ski out of storage.

9. Inspect for Damage or Wear Before Storing

Look for:

• Cracks in the hull
• Tears in the seat
• Corroded metal parts
• Loose clamps or fittings
• Signs of rust or wear

Catch small issues before they turn into expensive repairs after months of sitting.

10. Don’t Forget About Jet Ski Insurance

Many owners cancel or ignore their insurance coverage in the off-season. However, storage-related damages like theft, fire, or weather events can still occur.

Review your policy coverage with your provider and make sure your ski is protected year-round.

Get Connected to Jet Ski Maintenance and Repair 

Long-term storage isn’t just about throwing on a cover and walking away. A few hours of smart prep can prevent rust, protect the engine, and save hundreds—or even thousands—in repairs down the road.

When you follow these guidelines, your jet ski will stay in good condition, ready to ride when the season hits. And remember—a well-maintained ski is a safer ski.

If you find yourself in need of maintenance support or repairs, Jet Tek Water Sports is here to help. We can complete routine jet ski maintenance tasks like oil changes to hefty repairs like complete engine overhauls. Whatever type of service you need, we can get your jet ski back out on the water in no time. 

Frequently Asked Questions (FAQ)

1. Can I store my jet ski in the water during the off-season?

Storing a jet ski in the water for extended periods is not recommended. Continuous water exposure—especially in saltwater—can accelerate hull damage, corrosion of metal components, and lead to marine growth in the intake and cooling system. If dock storage is your only option, invest in a floating PWC dock or lift to keep the hull dry.

2. Do I need to change the oil before or after storage?

If your jet ski has a four-stroke engine, it’s best to change the oil before storing it long-term. Old oil can contain contaminants that may corrode internal engine components while sitting idle. Make sure to also replace the oil filter during this process for complete protection.

3. Should I start my jet ski occasionally during storage to “keep it fresh”?

No—starting your jet ski occasionally during storage can do more harm than good if not done correctly. Short engine runs may not reach full operating temperature and can lead to condensation buildup inside the engine. It’s better to fully prepare the ski for storage and leave it until you’re ready to ride.

4. How do I keep rodents and pests out of my jet ski during storage?

To deter rodents and pests:

• Close off air intake and exhaust openings using breathable covers or screens.
• Remove any food or trash from storage compartments.
• Consider placing rodent repellents (like dryer sheets or peppermint oil) near the ski, especially in garages or sheds.

5. Is shrink-wrapping better than using a standard cover?

Shrink-wrapping provides a tight, weatherproof seal ideal for long-term outdoor storage, especially in winter. However, it’s more expensive and less breathable than a high-quality marine cover. If you choose shrink-wrapping, ensure there is ventilation to prevent mold or condensation buildup inside.

6. What signs should I look for that my jet ski wasn’t stored properly?

Common signs include:

• Difficulty starting or battery failure
• Visible rust or corrosion on metal parts
• Fuel odors or leaks
• Mold or mildew under the seat
• Cracks or fading in plastics and seats

If you notice these, a full inspection and service may be needed before riding.