Winterizing a boat in Connecticut, in the order that matters

A boat that has been winterized properly comes out in April and goes in the water. One that has not comes out with a cracked block, a moldy cabin, or a bill. The difference is one long afternoon in October.

Connecticut makes this non-negotiable. Water expands about 9 percent when it freezes, and it does not care what it is inside when it does.

Get the water out of the engine, first and above everything

This is the job that actually matters. Any water left in a block, a manifold or a heat exchanger can crack it when it freezes, and that is usually the most expensive part of the boat.

On a raw-water-cooled engine, drain it and then run non-toxic propylene glycol antifreeze through the cooling system until it comes out the exhaust at full strength. On a closed-cooling engine, test the coolant loop for the temperature it is actually rated to and winterize the raw-water side the same way. Outboards mostly drain themselves when tilted down, but they still want fogging and fresh gearcase oil.

If you are not certain which system you have, that uncertainty is the reason to have a yard do it once and watch them.

Fuel, and where the water gets in

Fill the tank to about 90 percent and add stabilizer, then run the engine long enough to pull treated fuel all the way through. A near-full tank leaves little room for the air that condenses into your fuel on a cold night. If the boat runs ethanol-blended fuel, this matters more, not less: ethanol holds water until it cannot, and then drops it to the bottom of the tank where the pickup is.

Drain everything else that holds water

Freshwater tank, water heater, head, holding tank, livewell, washdown pump, air conditioning. Pump non-toxic antifreeze through the lines. Anything with a low spot holds water, and every low spot is a crack waiting for January.

Clean it as if you will not see it for six months

Because you will not. Wash the hull and get the growth off before it dries on. Empty the cabin completely: food, drinks, bedding, life jackets, anything fabric, anything paper. Leave lockers and the refrigerator propped open so air moves through them. Prop the cushions on edge rather than laying them flat.

Batteries out, or on a tender

Cold does not destroy a charged battery, but a battery sitting at half charge will freeze and split. Either take them out and keep them somewhere dry on a tender, or leave them in on a tender if there is power where the boat is stored.

Cover: shrink wrap, canvas, or a roof

Shrink wrap is cheap and effective outdoors, and it must have vents, or you have built a humidity chamber around your own upholstery. Canvas needs a frame with enough pitch to shed snow, or it pools, freezes and tears.

A boat stored indoors needs none of that, which is most of the argument for indoor storage: no wrap bill every autumn, no ice load, no wind, and the cabin stays dry without a fight.

Indoors or outdoors, honestly

Outdoor storage is cheaper and it works for a well-wrapped boat. Indoor storage costs more and takes the weather out of the equation entirely, along with the ultraviolet that is quietly ageing your gelcoat and canvas every summer it sits in a driveway.

The practical dividing line is usually value and hassle. A twenty-foot fishing boat that lives on a trailer is fine outdoors, wrapped. Something with a cabin, a lot of brightwork, or a number that makes you wince, generally is not.

Trailer, while you are there

Grease the bearings, check the tires including the spare, and take the weight off the suspension if you can. Trailer failures in May are almost always caused by something that happened in November.

Write down what you did

Tape a list inside the cabin: what you drained, what you fogged, what is in the exhaust, where the batteries went, which through-hulls are closed. In April you will not remember, and the list is the difference between a launch day and an afternoon of working it out.