Introduction: How to Winterize a Boat

About: I am a Middle School Technology Education teacher in southern Wisconsin.

This Instructable will teach you how to prepare a boat for a harsh mid-western winter.

Here's what you need:

  • Combination screw driver
  • A boat - in this case it is a '97 Malibu Response with a Black Scorpion engine
  • Anti-freeze, 3-5 bottles
  • A garden hose connected to a spigot
  • A 5 gallon bucket, ours has 2 feet of hose to attached near the bottom for draining
  • MerCruiser marine oil, oil filter, and oil filter wrench (optional, but since you're there you might as well do that too.)

Also pictured is a prop-puller and socket. This is not need for this instructable.

Step 1: Find the Hose

This boat in an Inboard, which means the engine is located in the center of the boat. Whereas outboard motors are mounted to the back of the boat.

Lift the engine hood and locate the water coolant hose. In this boat it is located on the driver side of the engine. It is the black hose with a brass fitting and a green stripe.

Loosen hose clamps with a screw driver and remove from brass fitting.

Step 2: (Prepare To) Start Your Engine...

Insert a garden hose into the water intake hose of the engine.

Turn the garden hose on before starting the engine. And let the engine idle until the water coming out of the back of the boat feels warm. 5-10 minutes.

As the engine heats up, open and prepare the bottles of anti-freeze.

Step 3: Adding the Anti-Freeze

When the water feels hot, it is time to remove the garden hose. Immediately, pour the anti-freeze into the same engine hose while the engine is still running.

Continue to pour anti-freeze until it pours out the back of the boat. Then shut off engine. Our boat used about 4 bottles of anti-freeze.

Replace the engine hose onto the brass fitting, which is much easier said than done.

Your boat is now ready for another cold winter. Don't forget to remove the battery and maintain the charge a couple of times over winter.

Winterize Challenge

First Prize in the
Winterize Challenge