Inspecting Middle-Aged Boats

A well-built boat will age gracefully, but after about 10 years, some components start to show their age and there are certain areas that need a closer look.

Seacock handle"Exercise" your seacocks a few times a year to keep them from seizing. You’ll also be aware of other problems, like this handle that rusted off, rendering the seacock useless.

Ed Anston, a member in Long Island, still remembers the day 10 years ago that he bought his boat: "I was so excited to finally be buying a new boat; all of the headaches of maintaining my 30-year-old cruiser were going to be a thing of the past. I imagined, aside from getting the bottom painted, I wouldn't have many yard bills." The years have passed quickly and Ed says that his expectations of low maintenance have largely been fulfilled. But lately he's begun to realize that in 10 years, some things beyond routine maintenance have to be addressed. His prop has hit its share of branches, a few port lights are leaking, and his bronze through-hulls are harder to open and close. "I have to keep a sharper eye on systems and components that are starting to need attention."

Compared to cars, boats hang around for a long time; according to the American Automobile Association, the average car is about 10 years old while, according to the National Marine Manufacturers Association, the average boat age is closer to 20 years. A well-built boat will age gracefully, but after about 10 years, some components start to show their age and there are certain areas that need a closer look. If your boat has passed the decade mark, here are some things to keep a close eye on.


Take a hard look at how your boat floats at a dock. Larger boats have waterlines that show how the manufacturer intended the boat to float — these waterlines usually correspond to where bottom paint is applied. Typically, the bottom paint extends a few inches up from the waterline. Sight your boat from aft; does it appear to list to one side? How about fore and aft? Does the bow dip or the stern squat at the dock? Boats often gain weight over the years, usually when "stuff" is brought onboard and never taken off. Anchors, chain, spare fuel or water tanks, tools, etc, can cause a boat to float off its lines. Not only does this affect performance, it might make it more difficult for bilge water to flow where it can be pumped out and can make the cockpit drains less effective. Redistribute or, better yet, remove the accumulated weight.

Engine Area

Depending on where you boat (fresh or saltwater), exhaust manifolds that are more than a few years old need to be inspected carefully; 10 years is about the outside limit in fresh water while manifolds in saltwater may only last half that. Rust streaks on the outside almost always mean rust inside that can't be ignored, at least not for long. A shop can remove the manifolds and pressure-test them, but if they're original equipment, it's good insurance to simply replace them.

p> Rusted exhaust manifold The lifespan of an exhaust manifold can be as little as three years in a warm saltwater environment. Eventually they rust from the inside and if they fail, water can get inside the engine and destroy it (Claim # 0801149).

Traditional stuffing boxes typically last decades, but the original packing won't. If you find yourself having to re-tighten the stuffing box often, it's time to replace the packing. Consider a newer high-tech type like Gore-Tex that lasts much longer and hardly drips at all. Check the hose clamps on the stuffing box, too; drips will corrode the underside of the clamps, which may be hard to see. Loosen and rotate them, as necessary, and replace any that are corroded.

Bilge pumps lead a tough life and they don't last forever. And it's not just the pumps — switches are notorious for checking out early and wiring can become corroded if the connectors are not waterproof or if the wire sheath has been nicked in the past. A slight voltage drop to the pump can seriously affect its performance. The best way to check the bilge pump system is to pour some water in the bilge and make sure the automatic switch actuates and the water gets pumped out. (Tip: There have been several claims for water damage due to bilge pump switches that got jammed by loose gear in the bilge.) If you want to go an extra step and have easy access to the pump's discharge, place a bucket there and see how long it takes to pump out a few gallons. A little math will show you if your pump is working as advertised; if you get four gallons in a minute in your bucket, multiply that by 60 to get gallons per hour (4 x 60 = 240). Because of voltage drops, friction in the hoses, and the distance the water has to be lifted, you may be surprised to learn that your pump moves nowhere near as much water as the manufacturer claims. This might be a good time to upgrade.

Gasoline hoses should be inspected routinely, at least twice a year. Run a clean rag over each hose; if the rag smells like gas, the hose must be replaced. Diesel hoses typically last longer, although any low spots that retain fuel may be more prone to leaking. Marine sanitation hoses are notoriously good at telling you when they need to be replaced. When the fateful time arrives, use smooth-walled quality hoses made for sanitation. With any hose replacement, it's a good idea to replace the hose clamps, too.

Belts are likely to have reached the end of their lives after 10 years of steady use. Look for black dust around the pulleys, which indicates excessive wear. It's a good idea also to carry spare belts.

Steering and control cables can be checked by flexing the cable and listening for "crunching." Look also for swelling and rust, which indicate a cable needs to be replaced. Don't forget to lube the steering rod if your system has a zerk fitting. Hydraulic steering hoses should be inspected for leaks, especially at connections. Some manufacturers specify replacing the hydraulic fluid at intervals because it can absorb water and cause internal rust.

Coolant wears out over time and the corrosion inhibitors lose their ability, causing pitting and corrosion inside the cooling passages. Extended-life coolants last for up to six years before they start to lose their effectiveness. Make sure you use the coolant specified by your manufacturer. It's also a good time to check the condition of the system's hoses. Bulging, cracking, and soft hoses need to be replaced; older hoses can collapse, causing an engine overheat. Check all the hose clamps and replace any that are questionable.


Over the years, props encounter their share of hits — a floating branch or two, a hard bottom, churned up sand, etc. Eventually they tend to get dinged and bent just enough that, while you can't see it, the damage will negatively affect your boat's performance; a banged-up prop can rob you of 10 percent of your speed and fuel economy. Ten years is a good time to remove your props and take them to a prop shop for checking and/or reconditioning. If your boat has a cutless bearing, it might be due for replacement. There should be little movement when you try to move the prop shaft side to side.


Electronic detectors, such as carbon monoxide (CO) and gas fume alarms, have a designed life expectancy. New CO alarms are required to let the owner know their useful life is over after five years; a 10-year-old boat should be ready for its second replacement. The sensitive electronics inside the alarms are less effective at detecting deadly CO after a few years. Replacing them is inexpensive insurance. Gas-fume detectors may not even last five years, because they’re typically mounted just above the bilge water.

Safety Equipment

Flares have a limited lifespan and most people will have replaced them several times by now (the flares are marked with their expiration dates). Flare guns, even if stored in a watertight container, should be opened and closed occasionally to check for corrosion.

Personal flotation devices (PFDs) don't last forever, either, especially if they are put away wet. Moldy PFDs should be replaced, and if you find any with chafed or cut straps, replace them too. Auto-inflatable PFDs should be carefully checked. Most have a green indicator showing they're armed. There is no set life for the arming mechanism, so at least inspect it and make sure it hasn’t gotten wet in the past. If you decide to re-arm it, it’s a good opportunity to see how it works; jump overboard or into a swimming pool with it on. Repacking and rearming is not difficult and will give you confidence in your equipment. If you have a throwable PFD with a line, take it out of its case and inspect it. Check closely for mildew, which can usually be cleaned up with vinegar.

Other Stuff

Some anodes should be replaced every one or two years (prop shaft, outdrive, etc), but there are some that last a lot longer. The 10-year mark is a good time to check the one in the water heater (not all water heaters have anodes) and any heat exchangers.

As they age, shore power cords and/or inlets wear out and are prone to arcing that can cause fires. Using your hand, check for excessive heat on the shore power cord at the inlet when the AC system is under a heavy load. Excessive heat — hard to keep your hand on it — indicates the cord and/ or the inlet needs to be replaced. Note that cords can suffer damage if they get caught between the boat and a dock or get yanked out accidentally. Run your hands along the (disconnected) cord, feeling for cuts and bulges, and inspect the connectors carefully. Replace any damaged cords or ends immediately.

Over the years, seacocks become stiff if they're not regularly "exercised." If it's been years since one has been opened and closed, it might be frozen, and a frozen seacock is useless. In that case, the boat will have to be hauled so the seacock can be disassembled, cleaned, and lubricated. If you make it a point to work the seacocks a few times a year, they're less likely to suffer this problem. While you're checking out the seacocks, don't forget to inspect or preemptively replace the hose clamps — it's cheap insurance.

Sailboat Rigging

A boat that is raced hard can go through a set of standing rigging in 10 years or less. Even a sailboat used for daysailing can suffer from cyclical loads that can cause stress cracks, and frequent exposure to saltwater can cause the swages to crack and corrode. Boats that sail in warm salty waters are much likelier to suffer than freshwater cool-weather boats. Depending in part on climate and frequency of use, running rigging (sheets, halyards, topping lifts, etc.) is usually nearing the end of its life at 10 years.

Deck Fittings

With caulked fittings, the boatyard rule of thumb is that after 10 years, the bedding owes you nothing. Depending on the type of caulk, 15 years is the outside limit. Many boatyards consider dark-hulled boats to be harder on bedding than light-colored ones because of the temperature differences. Carefully check around fittings and underneath those you have access to for leaks. Don’t forget to look for telltale signs of leaking around port lights.

The BoatUS Marine Insurance Loss Prevention Survey Program

Once a boat reaches 10 years old (and every five years thereafter), BoatUS Marine Insurance may choose — at our option — to have a survey, paid for by BoatUS, done on a boat. Mike Pellerin, the BoatUS vice president of underwriting, says that as a boat ages, it's often hard to recognize the gradual changes in its condition. The program identifies potential problems before they become costly or even dangerous, which benefits everyone.

To cite one recent example: A surveyor inspected a winterized boat and found a rusted oil pan that was leaking engine oil, which could have led to a seized engine and even fines for pollution discharge.