Boat owners must winterize engines and freshwater systems, especially when boats are stored ashore. In deep freeze states, boats stored ashore must be winterized earlier than boats stored in the water. When the temperature falls below freezing, if there is water inside your engine or gear case, the result can be a cracked block or housing and a repair bill that runs into the thousands. It is easy enough to prevent this unhappy circumstance by putting your boat's engine to bed properly at the end of the boating season.
At least twice a season, inspect any fittings above or below the waterline that could be letting water into the boat. All too often, skippers rely on bilge pumps to bail them out when they can’t visit their boats. The pump fails and the boat sinks.
If you can’t visit your boat regularly, consider using a buddy system with other boat owners to watch each other’s boats. A plastic thru-hull that was an inch or two above the waterline cracked and the weight of the snow lowered the damaged fitting to just below the surface. The boat gradually filled with water and sank.
In the winter, portable heaters are the wrong way to keep your boat from freeze damage. Boat U.S. marine insurance claims files confirm the assessment that the leading causes of winter vessel fires are unattended portable heaters and overtaxed electrical systems. Unattended heaters are easily tipped over by wave movement and other forces.
A couple of January's ago, a vintage 47-foot Chris Craft caught fire and burned to the waterline at a marina in Gloucester Point, VA. A subsequent investigation found that three portable electric heaters had been left aboard while the boat was unattended. Luckily, the fire occurred in daylight and was discovered before any nearby boats were damaged.That isn't always the case; there have been instances where entire marinas--including dozens of boats--were devastated after a single boat caught fire.
Never use any portable heater to protect your boat during winter lay-up. Portable electric heaters are one of the leading causes of marina and boat fires and should never be used on a boat. Improper use of electric heaters CAUSES boat fires. Once your boat is burning, it will likely spread to other boats in your shed or storage yard, and can quite possibly burn down the entire marina, resulting in loss of life and significant property damage.