How to Dewinterize Your Boat for the First Time In Season

It’s early spring in Arizona and that boat you winterized just a few months ago is now begging to be put back in the water, but does your boat need to be dewinterized first?

Summerizing; also referred to as unwinterizing or de-winterizing, a boat is a critical step before reintroducing your vessel to water. It involves the cleaning out of all winterization fluids and inspecting for damages that may have previously gone unnoticed or occurred during the cold months.

So, if your confident temperatures will consistently be above freezing and that warm Arizona sun is shining, follow these 10 easy boat summerization steps to get your back on the water quickly and safely.

A Step by Step Guide to Dewinterize Your Boat

Step 1: Take of the Tarp, Clean, and Inspect Your Boat

When taking off the tarp be on the lookout for any critters that may have shacked up in there while your boat was in storage. Chew marks, shredded paper or rodent droppings are all tell-tale signs that you’ll need to evict pests.

Clean your boat inside and out. Check the upholstery, bimini top, seats, and covers for any tears, rips, dirt, mold, rust, and anything else that doesn’t belong there. Whether you use a power washer or just a plain old scrub brush, be thorough to avoid problems later on.

Pro tip: Cleaning the boat is the best time to inspect the hull for new damage. Damage could have occurred during storage, but even minor damage prior to storage could now be exacerbated by the cold temperatures.

Step 2: Check All Fluid Levels

Oil, cooling system, and the hydraulic steering fluid reservoirs should all be checked to ensure they are at appropriate levels. If you didn’t change the oil and/or oil filter before winter, go ahead and change those now as well. 

Pro tip: Clean oil is gold or amber and dirty oil is black. Only run your boat with clean oil.  

Step 3: Inspect and Drain the Fuel System

Even if you did add fuel stabilizer, it's best practice to drain all fuel tanks in the spring. If your boat was in storage for any length of time you still run the risk of having stale fuel in the tank. It’s safer to drain the tank after storage and start fresh regardless of whether you treated the gas for separation in the fall.  

Carefully check the fuel lines for cracks and rust which can easily crack during freezing temperatures. Fuel lines, and the fuel tank, are very susceptible to rust. But if you filled up your fuel tank before winter it shouldn’t be a problem.  

Once you're sure the fuel system is free of damage, top off the tank with fresh fuel and change the fuel filter if not previously done during winterization. 

Step 4:  Clean the Distributor Cap

Remove the distributor cap, check for corrosion, and clean thoroughly. Rust and corrosion can get into this spot when it’s cold and damp and it needs to be cleaned completely. Reconnect tightly when done. 

Step 5: Check Belts, Cables and Hoses

Going from the extreme heat of an Arizona summer to the freezing or near freezing temperatures of the winter months can cause premature wear on vulnerable rubber belts, cables and hoses. Be sure to take an extra close look and replace them where necessary. 

Belts can be inspected by pressing down firmly to feel how much “give” they have. A belt should be taut and not have too much flexibility. If it does, replace it. Also inspect the pulleys. Pulleys accumulate soot when the belt is getting worn down, so a pulley with a lot of soot is a good indicator the belt needs to be replaced. 

Step 6: Check and Clean Battery

If you followed our Arizona Boat Winterization Guide and disconnected your battery in the fall it should have kept its charge. Simply clean any corrosion from the terminals and inspect it for damage before reconnecting it. Check that wet cells are filled with distilled water and use a battery tester to check the amps and volts. If the battery is low be sure it charges overnight before you take the boat out. If it won't hold a charge, it’s cheaper and easier to just replace it now. 

Pro Tip: When reconnecting your battery, always reconnect the positive side first to avoid causing a short in the system.

Step 7:Check Your Bilge Pump

Turn on the switch and make sure your bilge pump not only runs, but actually pumps water out of the boat. To do this; put the plug in your boat, then using a garden hose fill the boat with a small amount of water before turning on the bilge pump. It’s a little extra effort but if it isn’t working, it’s better to know now than when you're taking on lake water!

Step 8: Get Water Flowing Through the Cooling System and Inspect the Engine

To properly inspect the engine, you’ll need to get water flowing through the cooling system then start it up. But, before you grab the garden hose, do a visual inspection of the engine and engine components. If any water was left during freezing temperatures, there will be cracks and damage from water expansion. If you find cracks, stop now and decide how to best repair your boat.

Next, inspect the propeller and make sure it’s snugly fastened and rotating properly. Empty the strainer and check rubber parts and the impeller for damage. 

Pro Tip: Before you start any outboard motor after it has been in storage, first pull the plugs, spray some WD-40 in the heads, leave the plugs out and slowly turn the motor by the flywheel or prop. If everything turns smoothly, then you can go ahead and install plugs. Add water and start it up.  If you do this your motor will last longer you may just save yourself from serious engine damage.

To get water flowing through the cooling system, clear debris from the water lint screens and attach a garden hose to the hose connector of your engine or with water muffs.  Slowly turn on the garden hose. Prime the fuel line. And start the engine. If you don’t see water rushing out right away, IMMEDIATELY TURN THE ENGINE OFF to avoid damage. This indicates that the impeller is not pulling water into the engine properly. Run the motor for up to 10 minutes until water is clear and any smoke due to fogging oil from winterization dissipates.  

For a more detailed guide on starting your outboard motor, click here. 

Pro Tip: This is a good time to check your kill switch; pull the lanyard and make sure it actually cuts the engine.

Step 9: Inspect and Paint the Bottom of the Boat 

Take a good look at the hull, fiberglass, and all around the outside of the boat. Cracks may have been there before winter and have now grown larger because of the cold weather or there may have been damage during storage. Next, take the time to sand and scrape the bottom of the boat and apply an anti-fouling paint. Anti-fouling paint keeps your boat clean and prevents rot. 

Step 10: Check Safety Equipment and Trailer

Take stock of your safety equipment and look for expired fire extinguishers and anything that can be replaced in your first aid kit. Count life vests and store the required amount on board. Check flares, horns, lights and stow legal documents, such as government boating certificates, licenses and necessary registrations are all up to date and on board. Check that the electronic accessories like navigation units, the Fish Finder, and stereo are all in working order.

The trailer is often overlooked. Check brackets, tail lights, wheel bearings, and tire pressure. 

Final Thoughts

Properly dewinterizing your boat is as important as winterizing it. A thorough inspection will detect cracks and damage that happened over the winter months and prevent emergencies later on. Once you’ve gone through these steps, it’s time to get the boat back on the water and have some fun in the warm Arizona sun.