Keep Your Scuppers Clear This Winter

Winter in most parts of the country means freezing temperatures, which means ice. Expanding ice can sink a boat in several obvious ways, such as cracking a strainer or thru-hull fitting. But it can also block a cockpit scupper, allowing the weight of subsequent snow and rain to push the stern of the boat down enough to cause water to backflow through fittings or exhaust openings. When enough water backflows, the boat can sink. Even if your boat is stored ashore, clogged scuppers can cause damage when accumulating water finds its way into the interior. The best way to keep scuppers ice-free in the winter is to make sure they're clear of debris so water drains quickly without freezing. And the best way to do that is to visit your boat often to check them. Even if you cleaned the drains last autumn, you're liable to find that leaves and other debris have mysteriously found their way back aboard. Installing a $2 mesh designed to fit into a roof's downspout can help keep your scuppers flowing between visits. You can make your own or buy one like the Expanded Leaf Strainer shown here. It's made by Amerimax and is available at home supply stores like Lowes and online at

Batteries and Cold Weather

For those of you in California, Florida, and the Gulf States (lucky readers in Hawaii can pretty much ignore this), chances are that even if temperatures don't go below freezing, it can still get cold enough to affect your battery's performance. The last thing you need if you're heading out into chillier waters is a dead battery and no way to get home. To start with, flooded-cell batteries will lose up to five percent of their charge each month in cool weather, so if the boat is sitting and the batteries are not on a charger, you're already at a disadvantage. Even more importantly, batteries lose up to 35 percent of their capacity when temperatures fall near freezing, so older batteries that do fine in warm weather may not be able to generate enough amps to turn the engine over in cold weather. In addition, the engine oil is more viscous, so it takes more energy to crank the engine in the first place. If you're uncertain of how much capacity your battery still has, take it to an auto parts store, and have it load tested. Keep each cell filled with distilled water (for wet cells only; AGM and gel batteries are sealed), and clean and tighten the lug connections to deliver as much current as possible to the starter.

Shorepower Fail

If you leave your boat in the water this year, chances are you'll be plugging into shorepower. But before you do, inspect the connection to your boat. A recent Seaworthy study found that 17 percent of boat fires were attributed to the AC system, and the shorepower system was responsible for many of those. Shorepower inlets are exposed to water, and the connections are subject to vibration and corrosion. A particularly vulnerable link is the terminals at the back of the boat's shorepower inlet where the boat's wiring is connected. Those terminals are also usually surrounded by combustible material. An overload in the shorepower system can easily overheat these wires and cause a fire. This winter, inspect your shorepower inlet. If you see discolored contacts, stop using the cord immediately and fix or replace it. It's very possible that the inlet wiring inside the boat is damaged, so inspect that as well. Be careful not to overload your shorepower system with high-amperage appliances. (This is yet another reason to never use a heater to winterize.) Check along the cord, too, and look for gouges and crushed spots that can create heat.

Wire Nut Fail

We've said many times in these pages that crimping is the proper way to make wire connections. Crimping mechanically grips the wire strands so they won't easily come out, and the sealed type protects the connection from corrosion, which can lead to heat or failure of the circuit. Wire nuts — the kind used in cars and around the house — should never be used on boats. While they're easier to use (crimp connections require an inexpensive crimp tool), they simply don't hold well. Wire nuts are designed to be used with solid wire, not the stranded kind used in boats. For a wire nut to tighten correctly, it must cut threads into solid wire. Wire nuts can't tighten stranded wire adequately, and the nuts may actually cut some of the strands, leaving you with less wire and more resistance (heat). Finally, they are difficult to seal against water and corrosives. The bilge pump (top right) was rendered useless when the installer used household wire nuts and the connection simply came apart. The bundle (bottom right) has many broken strands, and the wires are corroded.

Winter Fuel System Check

The Seaworthy editors spent a great deal of time in the claim files in the past few months looking for the causes of fire aboard boats of different types. Not too surprisingly, gasoline plays a role in many of those fires, if not in how they start, then in providing the fuel to keep the fire going. Deteriorated hoses, corroded hose clamps, loose fittings, and leaking fuel filters can all contribute to a fire. So if you have a gasoline engine on your boat, whether an inboard or an outboard, take the time this winter to get up close and personal with your fuel system and make sure everything is in good working order. This is a good time of year to get down in the engine compartment and simply sniff. If you smell gasoline when the boat has not been used for a few weeks or more, you definitely have a sneak leak. You need to track down where that smell is coming from. Start with the deck fills, if you can get to them, and trace as much of the fuel system as possible. Pay particular attention to the fuel filters, fuel pump, and fuel hoses. Old fuel hoses can become porous, allowing fumes to seep out that can be dangerous when the engine is operating. Wiping each fitting with a clean rag and smelling it will help you locate a porous hose or a small weep that might otherwise miss detection. Fix it and go into next season confident that gasoline is going to be where it should be — and not where it shouldn't. 

— Published: January 2016

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