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17 Must-Do Spring Boat Maintenance Tasks

Last winter was likely a flurry of activity as you put your boat to bed, spending hours checking off every conceivable chore to make sure it was ready come spring. Or maybe, like a lot of people, you did just enough to make sure the boat wouldn't be damaged by the cold but left a few things for spring.

If so, you're in the right place. Our BoatUS Marine Insurance claims files are full of what can happen when boaters, anxious for the first outing of the year, forget to do some of the things they didn't have time for last winter. Here are the things you'll want to make sure you check before launching this spring.

How to Replace Anodes and Zincs on a Boat

Check for deteriorated anodes. They disintegrate over time and give a good indication of what would happen to vital underwater machinery if the anodes weren't there. If they're about half gone, replace them. Note: If the anode has vanished or has been reduced to powder, check the other metal underwater surfaces to ensure they didn't also suffer from galvanic corrosion. For outboards and sterndrives, if you buy the set, you'll know exactly how many need to be replaced; some of them can be hard to see. Anodes that disappear in less than a season may indicate a problem with the boat's electrical system. Look first for chafed DC wires or battery cables, which also can cause a fire. Keep in mind that corrosion is not usually covered by insurance.

Watch Video: Replace Sterndrive Anodes

Deteriorated Anodes

Inspect props. Look for dings, pitting, and distortion that can create excessive vibration and can loosen everything from screws and bulkheads to dental fillings and can damage the transmission. Make sure cotter pins are secure. Our claims files have several (sheepish) instances of on-water towing because props fell off. Bent props, incidentally, can usually be made like new by a prop shop. Check the cutless bearing on inboard-powered boats by gripping the shaft and trying to move it from side to side within the bearing. Looseness indicates the bearing probably needs to be replaced.

Watch Video: How to Replace a Propeller

Clean Propellor

Inspect the hull for blisters and stress cracks. Blisters are easier to see just after haul out, but any you see now should be dried, sanded, and filled. Large blisters may require professional attention. Stress cracks mean something is flexing and cracking the gelcoat. Those problems may need to be addressed by a marine surveyor or repairer.

Outboards, Inboard And Sterndrives

Check lower-unit lube. Hopefully you drained and filled the lower unit lube last winter, but if not, check the lube level and condition. Milk-chocolate-looking oil indicates a bad seal that allowed water in, and if it's not replaced, your lower unit can be destroyed.

Watch Video: Change the Oil in Your Lower Unit

Filling Gearcase

Replace the water pump impeller. After a couple of years, these are living on borrowed time, and when they fail, your engine will overheat, and your first spring outing might be a short one.

Check belts for tension and wear. Loose belts squeal and won't last long; worn ones can leave you stranded.

Check steering and power-trim oil levels. Low levels can cause reduced performance and damage the pumps.

Watch Video: Inspect Steering System

Inspect the outer jackets of control cables and linkages. Cracks or swelling indicate corrosion and mean the cable must be replaced. Otherwise it could fail and you can lose control of your boat. Don't try to remedy the problem by squirting lubricant into the cracks or wrapping duct tape around the outer jacket; most lubricants are incompatible with what the manufacturers used and will only make things worse.

Jump Cable

Inspect stuffing boxes. Check the engine shaft and rudder stuffing boxes for steady leaks and looseness. Prop-shaft stuffing boxes shouldn't leak at all at rest. (Our claims-file analysis showed that leaking stuffing boxes are responsible for a significant number of sinkings.) If leaking can't be stopped by tightening the nut, repack the packing or gland. Caution: Overtightening the nut may prevent leaking underway, but it will burn out the packing material and may damage the shaft.

Watch Video: How to Replace a Stuffing Box

Stuffing Box

Inspect rubber outdrive bellows. Look for cracked, dried, and/or deteriorated spots (look in the folds). Swiss-cheese bellows have sunk many a boat. Keep in mind that some boats may have several different bellows.

Check bilge pump operation. The best way to check the entire system is to put some water in the bilge so you can make sure the switch actuates and the pump gets the water out. If your boat came through winter with water already in the bilge, find the leaks and fix them. Bilge pumps are designed only to remove nuisance water — not to keep your boat afloat.

Watch Video: Replace Your Bilge Pump and Switch

Bilge Pump Switch

Check the fuel system. Inspect fuel lines, including fill and vent hoses, for indications of softness, brittleness, or cracking. Any that are suspect should be replaced with U.S. Coast Guard-approved A1- or A15-certified fuel hose. Fuel hoses for gasoline should be double clamped. Pay attention to fuel-line fittings, too — another source of dangerous leaks. Use your finger and look for stains and fuel smells under or around the fitting.

Fuel System

Check the electrical system. Clean and tighten electrical connections, especially both ends of battery cables; nearly 10 percent of calls to TowBoatUS are for dead batteries. Wire brush battery terminals and fill cells with distilled water. Loose connections can "arc," which creates an enormous amount of heat and are a fire hazard. If you have wingnuts on your battery, replace them with nuts that can be tightened properly.

Watch Video: How to Use a Multimeter to Isolate Electrical Problems

Inspect safety gear. Check fire extinguisher gauges for fullness and for expiration; if they're past that, replace them. Take a careful look at them and see if they're mounted where you'll most likely need them. Can you get to them if there's a galley fire? Engine room fire?

Check the dates and replace outdated flares. Keep old flares aboard as spares if they're in good condition and not too old. Store in a safe place designated for expired flares. Flares expire 42 months after their manufacture date, not when you bought them, so check the dates when you buy new ones. Test smoke and carbon-monoxide alarms.

Fire Extinguisher

Trailers

Inspect tire treads and sidewalls. Our claims files show that almost half — 44 percent — of BoatUS TRAILER ASSIST® calls were for flat tires. Most trailer tires don't wear out on the tread, they die of exposure to the elements. Look for cracks in sidewalls, which means they need to be replaced. Use a gauge to check pressure and don't forget the trailer's spare.

Watch Video: Learn How to Change a Boat Trailer Tire

Trailer Tire Cracking

Check bearings. One in five TRAILER ASSIST® calls are for bearing problems. Inspect them carefully, and if they rumble or won't turn easily, they probably need to be repacked or replaced. Keep a spare set so you can replace them on the road if necessary.

Watch Video: Replace Wheel Bearings

Checking Wheel Bearings

Test brake, tail, turn signal, and back-up lights. Clean/tighten connections or replace bulbs to assure that all are operating properly. It might be a good time to upgrade to waterproof LED lights. Make sure the white ground wire is securely attached to the trailer's frame or you may be chasing frustrating light problems.

Watch Video: Troubleshoot Boat Trailer Lights

The One Thing You MUST Do

Data from our BoatUS Marine Insurance files shows that one of the most common mistakes in the haste to launch can sink your boat.

Make sure the engine intake sea strainer and any other thru-hull openings are properly secured. Every year, boats sink just after launch because someone forgot to reinstall strainers for raw-water cooling after they were winterized. Also, if they weren't properly drained last fall, they could've been damaged by ice over the winter. Check for worn-out hose and rusted hose clamps while you're there. If your boat is trailered, make sure to install the drain plug you may have removed last fall before you launch.

Charles Fort

Charles handles our exclusive Seaworthy in-depth tech feature in every issue, our videos, and our investigative features. He helps with dispute-mediation and writes our Consumer Protection column. A member of the National Association of Marine Surveyors, he’s on ABYC tech committees, and has a 100-ton U.S. Coast Guard license. A sailor who went cruising with his family, he now lives in California.