If you have a copy, great. If you don&#39;t, it would be a good idea to get one. You&#39;ll need it to replace fluids and parts properly. Never take apart anything without consulting the manual first.<p>The engine is the heart of the boat, and since it will most like take the greatest amount of time and be the messiest, start here. If you didn&#39;t change the oil at the end of last season, do so now. After running your boat all summer, it&#39;s likely that water, acids and other byproducts have built up. It&#39;s important to change the oil to prevent corrosion and excessive wear which can lead to loss of power, poor fuel economy or engine failure. At the same time you change the oil, be sure to change the oil filter. Change the oil in transmission or the outboard&#39;s lower unit as well.</p><p>Next, flush the cooling system and replace the antifreeze with a 50/50 ratio of water to coolant.</p><p>Finally, replace the batteries and perform a thorough engine test.</p>Check your bimini top, seats, covers, and other vinyl and canvas items for tears, mildew and dirt. Repairs tears and holes, and then clean with the proper cleaner for canvas and vinyl.<p>Carefully inspect the hull for blisters or other chips and cracks as well as for chalky residue. If you find blisters, repair them. If the boat&#39;s hull is chalky, it could indicate oxidation. Determine the <a href="https://www.thoughtco.com/boat-maintenance-gelcoat-oxidation-2747259" data-inlink="rtF7Slf8fkRMdTqEqUMQdA&#61;&#61;" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">level of oxidation</a>, and then <a href="https://www.thoughtco.com/gelcoat-restoration-and-repair-2747254" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="2">restore the boat&#39;s gelcoat</a> to its original luster. Then, throughout the summer, follow the <a href="https://www.thoughtco.com/naming-a-boat-2747304" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="3">gelcoat maintenance plan</a> to keep oxidation at bay.</p><p>First clean your boat&#39;s exterior using a marine safe cleaner from a marine supply store. Then, apply a fresh coat of wax according to the instructions in the <a href="https://www.thoughtco.com/naming-a-boat-2747304" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">gelcoat maintenance plan</a>.</p>Inspect and replace windshield wipers if necessary. If the wipers are in good condition, apply a rubber lubricant to protect them from the harsh marine environment. Some experts recommend stowing wipers until you need them to keep them in good condition longer.Known as brightwork, metal and teak enhance the look of your boat. If it&#39;s dull, your boat will not have the same visual appeal as it might otherwise have. Also, prolonged neglect of metal and teak can result in pitting and eventually compromise the integrity of the materials and their intended use. To protect the metal, use metal polisher like Never Dull. For teak, it is usually recommended that you sand it and then apply stain and varnish.Bring all the electronics back on board and do a thorough test to be sure they are working properly. Test the radio, GPS, compass, depth finder, and any other marine electronics.Whether you have an open deck or cabin with full galley, clean the area thoroughly to remove dirt and debris.