However early or late you have to winterize in your region, it is a wise idea to go over your houseboat from top to bottom before putting it away. Little problems that may have arisen during the boating season can become big problems over the winter months. Your marina can help put you in touch with a certified boat mechanic so you can sleep easy at night knowing everything was done correctly.
1. Start on the outside of your boat.
Look for signs of cracks in both the fiberglass and any caulking. Pay close attention to rails arches and windows. Water can find its way in, freeze, and make the cracks larger over the winter months. Check roof drains to make sure they are clear of debris and working properly. Check canvas and canvas ties. The winter months tend to be windy; if you have loose canvas it can be damaged if left to flap around in the wind. Remove ceiling fan blades and any loose items from the top deck and store them inside. Tie top deck furniture to the railing if you opt not to move it inside for storage. Check shore power cables for corrosion on the connections. Also, make sure they are tied to the railing in a way that takes the weight off of the connections.
Make sure your boat is disconnected from dockside water. Check all dock lines for condition. Remember, during the winter months there will not be as may people walking by your boat to spot a problem. Check the zinc anodes on the outdrives. If they are below 50% replace them. This can be done by trimming the drives up and using a dive mask. Be careful to not drop your tools and parts. Be sure to trim your drives down and straighten the rudders. If you leave the rudders of the drives trimmed up, it can place stress on the drive boots and cause them to start leaking. Check hatch drains to make sure they are clear of debris.
2. Check your engine compartment and bilge areas.
Look over all your hoses for cracks; make sure hose clamps are tight. Make sure the bilge is clean of debris that could get caught in a bilge pump and cause it to fail. Check the float switches on all bilge pumps. Lift the switch and make sure the pump comes on. Look for signs of any leaks, both lake water and fresh water, from the water system. Change engine oil in your drive engines and generator. Check battery fluid level and connection. Make sure the connections are clean and tight. If the batteries are low fill with distilled water. Check the zincs in the heat exchangers if your boat is equipped with closed engine cooling systems. Be sure to add fuel stabilizer to your fuel system.
3. What to look for in the cabin.
Check all windows to make sure the tracks are clean and free of debris and are locked. Check HVAC return filters; replace if dirty. Remove the keys from your ignitions and place in a safe place. This prevents someone form accidently starting the boat after everything has been winterized. This is a good idea on the newer boats with push-button start switches. Remove any perishable food items or anything that could freeze from the pantry or other storage areas. Nothing worse than finding a 12-pack you left in the cabinet froze and busted over the winter, spilling its contents all over the boat. If you do not plan to leave any heat on over the winter months it is good to at least run a dehumidifier. If you do not wish to run a dehumidifier at least place some of the Damprid containers around the boat. This keeps damp musty smells at bay.
4. Some general suggestions.
Make sure the marina has your current contact information and an emergency contact number. It is also a good idea to make sure they have a way to gain access to your houseboat in an emergency. Check your insurance policy. In some of the northern states, your insurance may not pay for damage done to the boat caused by harbor freezing.
I like to take pictures of each room, exterior and dock lines before leaving my boat for winter storage. These are photos I hope I never need, but in the event something does happen you will be glad you have them.