I don’t think there is a boat owner who doesn’t have a “to do” list. And there’s guaranteed to be a couple of items that never seems to get crossed off — those things we meant to fix in spring — when we were rushing around getting ready to open up the cottage — and in the summer, when we were having too much fun to fix anything but major problems. Well, there’s no better time to whittle down that list than over the winter. But winter is also the perfect time to catch up on cleaning, painting and go over all the systems we rely on during the rest of the year.
Take perishables, cushions, life jackets and books — anything that will retain moisture — off the boat. Leave locker doors open to ensure adequate airflow. Scrub the boat inside and out. Attack those stubborn stains. If you’ve got an inboard motor, why not give it a pressure cleaning to remove accumulated grease? This is the time to do a really serious cleaning and the chance to get into those hard-to reach areas that don’t normally get attention. Go over every square inch and use plenty of rinse water.
Take the time to go over every mechanical system and inspect and fix problems and potential problems. For those with an outboard motor — especially if the engine hasn’t been serviced for several years, why not get a professional mechanic to give it a good going over? Spark plugs, pump impellers, thermostats, zincs and gear oil must be checked and replaced on a regular basis. For those with inboards, check under the engine for oil, fuel or water leaks. Check belt tensions, examine all hoses for wear and leaks and replace as necessary. Change engine and/or transmission oil and filtres. When was the last time the in-line gas filter was checked? Consider coating cylinder walls with fogging oil to prevent rusting. What kind of shape are your built-in fuel tanks? If they’re marginal, consider replacing them. Check all engine controls, instruments and switches and fix those that aren’t working. Test alarm systems. Make sure the steering system is fully functional. Examine all parts for rust and wear. Lubricate as necessary. Test and lubricate (with vegetable oil) all thru-hulls and check all hoses for soft spots, cracks and ensure hose clamps aren’t rusty. (There should be two hose clamps in good shape on each thru-hull hose.) Look for and replace cracked O-rings — then lube the good ones with silicone grease.
You’ve already checked out the engine electrical system, but try all the electrical switches and repair as required. Follow the wiring and look for and redo corroded connections. Make sure terminal blocks, screws and fuses are corrosion-free. Test the navigation lights and hit the bulb sockets with a little sandpaper if there’s any corrosion. What kind of shape are your batteries in? Check levels, make sure terminals are clean and tight. Are the batteries holding a charge? Time for replacement? This is a good time to re-do that haywired electrical connection you threw together when you were in a hurry last summer, or to sort out that loose wire that’s been dangling from the dash.
If you have a head, check to make sure it is functioning properly. Fresh (drinking) water systems should be drained and flushed every few years. If the water tastes lousy, perhaps take more serious cleaning action or replace the tank. Check the water pump operation (replace impeller if required) and check lines and connections for leaks. If you’ve got a cook stove, check its operation and test it and the fuel lines for leaks. If you’ve got a propane, gas and/or carbon monoxide sniffer, check these items are working. Clean your fridge, and leave the door propped open with a tray of baking soda or a cup of instant coffee crystals to keep things
Source: http://cottagelife.com/environment/4-ways-to-maintain-your-boat-in-winter