Winterize Personal Watercraft (PWC): Great Plains Edition

If you ride a WaveRunner, Sea-Doo, Jet Ski, or similar personal watercraft on Great Plains lakes, it’s time to put it to bed for the winter. Yesterday we covered general boat winterization; today we’re drilling into the specific steps and differences for jet-drive personal watercraft.

Many PWC engines are self-draining and compact, which sometimes leads owners to skip winterization altogether. That’s an expensive gamble. A few minutes of prep now helps you avoid cracked housings, gummed-up fuel systems, and dead batteries when the water warms up again.

Throughout this article you’ll find links to solid PWC-specific resources and manufacturer guidance:

How PWC Winterization Differs from Boats

Personal watercraft share the same basic goals as traditional boats—get water out, protect the engine and fuel, and store everything clean and dry—but the details are different:

Jet pump instead of propeller. Your cooling water flows through the jet pump and exhaust. Flushing and draining are done through a dedicated flush port and by tilting the craft, not by pulling a drain plug on a big block or outboard.
Self-contained hull. Most PWCs don’t have bilges, livewells, or freshwater systems. Instead, you’re dealing with an enclosed hull and small storage compartments that can trap moisture and gear.
More exposure to rough use. PWCs often see hard acceleration, shallow water, and beaching. That makes careful inspection of the jet pump, intake grate, and hull especially important before storage.
Model-specific antifreeze needs. Some manufacturers (and local dealers) recommend running non-toxic RV/marine antifreeze through the cooling system in freezing climates, while others design their skis to self-drain and say antifreeze isn’t required if you follow their procedure. Always follow your owner’s manual first.

Think of your PWC as a compact, high-performance jet boat: it needs the same respect as any other engine-driven craft, just in a tighter package.

Step 1: Start With the Manual and a Safety Check

Every expert PWC winterization article starts here: read your manual. Sea-Doo’s official guide and independent service shops stress that different cooling layouts, 2-stroke vs. 4-stroke engines, and supercharged models all have unique requirements.

Before you start:

Park the PWC on a stable trailer, lift, or drive-on dock with the bow elevated.
Remove the lanyard and follow any lock-out procedures the manufacturer recommends.
Gather supplies: marine/RV antifreeze (if required), fuel stabilizer, fogging oil, basic tools, rags, and a quality cover.

Step 2: Clear the Gear and Compartments

Before winterization, strip the ski down to the basics.

Empty storage compartments. SkiSafe’s checklist begins with removing towels, ropes, and loose gear so compartments can be cleaned and dried: SkiSafe – 10 Steps to Winterize a PWC/Jet Ski.
Crack lids for ventilation. Many techs suggest leaving hatches slightly open (but not wide enough for critters) to prevent mildew.
Check for water inside the hull. Remove drain plugs and let any trapped water escape before moving on.

Step 3: Drain the Cooling System

PWCs use the surrounding lake water to cool the engine. If that water stays inside over winter, it can freeze and crack components.

EZ Dock explains a common method for flushing water from the system:

With the bow raised, start the engine and run it in short 20–30 second bursts, then shut it down and allow water to drain out the exhaust and pump.
Repeat until little or no water is coming out of the outlet. Their step-by-step jet ski guide is here: EZ Dock – Winterizing a Jet Ski.

Sea-Doo’s factory instructions add a freshwater flush through a dedicated connector on the stern, followed by a short high-RPM burst to blow out remaining water: Sea-Doo – Winterizing Your Sea-Doo.

Important: Never run a PWC engine for long periods without cooling water, and always follow the time limits and procedures in your manual.

Step 4: Antifreeze (If Your Manual Calls for It)

In places where temps reliably dip below freezing—like much of the Great Plains—many dealers and dock services recommend circulating non-toxic RV/marine antifreeze through the flush port to displace residual water.

Deaton’s Docks and EZ Dock both detail a similar process:

Mix RV/marine antifreeze with water in a bucket.
Connect a hose from the bucket to the PWC flush fitting.
Run the engine briefly while the mixture is drawn through, then shut down when colored antifreeze exits the exhaust. See: Deaton’s Docks – How to Winterize Your PWC.

However, some brands and models are designed to self-drain and state that antifreeze is unnecessary when proper draining procedures are followed, especially for indoor storage. That’s why manufacturer guidance (and sometimes dealer advice) takes priority over generic steps.

Step 5: Fuel System and Engine Protection

Fuel and internals need just as much attention on a PWC as on a bigger boat:

Fill the fuel tank and stabilize. A nearly full tank reduces condensation, and fuel stabilizer prevents varnish and phase separation over the off-season. EZ Dock and SkiSafe both emphasize filling the tank and running the engine to circulate treated fuel through the system.
Change engine oil and filter (4-stroke). For 4-stroke PWCs, follow your manual’s oil change procedure before storage so acidic, moisture-laden oil is not sitting in the crankcase all winter.
Fog the engine. Many winterization guides recommend fogging oil sprayed into the intake or cylinders to coat internal parts and prevent corrosion, especially on 2-stroke engines or skis stored in damp locations. Bell Performance offers a good explanation of fogging benefits in their jet ski article: Bell Performance – Winterizing a Jet Ski.

As always, follow the exact fogging and oil-change steps for your make and model. Supercharged PWCs can have extra requirements.

Step 6: Jet Pump, Steering, and Corrosion Control

Your jet pump is your “propeller, gearbox, and drivetrain” all in one compact unit. Winter is a good time to give it some attention.

Flush and inspect the jet pump. Clean sand, weeds, and debris from the intake grate and nozzle, then rinse and dry. SkiSafe recommends washing and inspecting the pump to prevent corrosion and catch damage early: SkiSafe – 10 Steps to Winterize a PWC/Jet Ski.
Lubricate moving parts. Apply marine-grade lubricant to steering and reverse linkages, the jet nozzle pivot points, and any exposed metal per your manual.
Look for impact damage. The Great Plains’ shallow, rocky launch areas are hard on hulls and pumps. Use winter layup as your annual “go over it with a flashlight” inspection.

Step 7: Battery, Cleaning, and Covering

Battery Care

Disconnect and remove the battery. Most PWC guides recommend taking the battery out of the ski and storing it in a cool, dry location.
Use a smart charger. A maintenance charger or tender keeps the battery topped up without overcharging, so you’re not buying a new one every spring.

Clean and Protect the Hull

Winter is the perfect time for a deep clean. EZ Dock’s checklist includes washing inside and out, drying thoroughly, and applying wax to protect the hull from UV and moisture during storage: EZ Dock – Winterizing a Jet Ski.

Rinse off dirt, algae, and mineral deposits.
Clean under seats, around handlebars, and in all storage compartments.
Dry thoroughly, then wax the exterior shell.

Cover and Store

Use a fitted cover. Choose a well-fitted PWC cover that keeps out dust, UV, and critters but still allows some ventilation.
Indoor vs outdoor storage. Riva Miami and BoatUS note that heated or indoor storage is ideal, but outdoor storage on a trailer or floating dock can work if the ski is fully winterized and covered: Riva Miami – How to Winterize Your Sea-Doo.
Great Plains note: If you store outdoors, plan for high winds. Strap the cover securely, and consider additional tie-downs so a Kansas gust doesn’t turn your cover into a kite.

Quick PWC Winterization Checklist

Read the owner’s manual and note any model-specific steps.
Park the PWC securely with the bow elevated; remove the lanyard.
Empty storage compartments; clean and dry them.
Drain the cooling system using short engine bursts with the bow raised; perform any freshwater flush the manual calls for.
If recommended, run non-toxic RV/marine antifreeze through the flush port until it exits the exhaust.
Fill the fuel tank, add stabilizer, and run briefly to circulate.
Change oil and filter (4-stroke), and fog the engine as directed.
Flush and inspect the jet pump; lubricate steering and linkages.
Remove the battery and place it on a smart charger indoors.
Wash, dry, and wax the hull; cover the ski securely for storage.

Prepper Angle: A Small Craft With Big Potential

On the Great Plains, a personal watercraft isn’t just a toy—it can be a fast, shallow-running platform for scouting, fishing, or grid-down transport when reservoirs and rivers become your highways. But like any high-performance tool, it only serves you well if it’s ready.

Set aside an hour or two to winterize your ski using your manual and the guides linked above. When spring finally breaks and the ice retreats from the coves, you’ll be able to hit the starter and head out—while everyone who skipped winterization is standing in line at the repair shop.

Prepper on the Plains

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Personal Watercraft Winterization