The spring commissioning rush is about to get underway across much of the country, which means many of us will be crawling around our boats from the rigging to the engine room.

Yet there are always areas that get overlooked – and those failures can come back to call in unpleasant ways, from nasty odors to system failures.

With boats getting increasingly more complex, it is getting tougher to inspect and maintain everything, especially if you do the work yourself. So take a minute as you make your lists this season to identify areas that you have not seen in awhile and perform some basic maintenance.

From the bilge to the engine boot, here are five areas that can often use a set of eyes before you take to the water.

The inside of a winterized boat – often shrink wrapped or covered with a tarp – can be a fertile breeding ground for mold. Inadequate ventilation increases humidity and helps fuel the spread of mold and mildew spores.BILGES AND PUMPS

Many of us pull up a cabin sole access panel, check for water in the bilge and then go our way. We are used to seeing brown or black sludge with an odor.

But bilges really should be cleaned, especially if water from the ice box or shower lands there (if you really want an olfactory experience, spill some milk in the refrigerator, let it drain into the bilge and age).

Take the time, early in the commissioning process, to thoroughly scrub out the bilges with a good bilge cleaner. It will keep the smell at bay throughout the season, and keep the float switches on your bilge pumps healthy. Speaking of, make sure those pumps and their switches are working – when you need them, you really need them.

PLUMBING BELOW THE WATERLINE

Most boaters do some kind of plumbing check as part of their spring commissioning efforts, but focus hard on the systems below the water line. If something is working, we tend to leave it alone, but problems here can yield the worst consequences.

Thru-hulls need to be exercised to ensure they operate smoothly – all of them. With the number of systems on boats proliferating, the number of thru-hulls is also growing. Make sure you know where they are, what they do and that they are working properly. You should also have a wooden safety plug attached to the thru-hull, in case one fails.

During winter, the hidden and protected environment inside the boat provides a happy home for mice and other small animals to escape the cold.Hose clamps should be inspected for signs of corrosion. Many clamps, especially cheaper ones, are advertised as stainless steel, but the worm screw fastener is made of mild steel and can corrode. Use an adjustable mechanics mirror on a handle to look behind the hose at the backs of the clamps – places not regularly inspected.

Also, check the hoses for signs of cracking or softness. Hoses sometimes have the inner liner separate from the outside and will block the flow through the hose.

CORED DECKS

Topside leaks can be insidious. Sometimes it's hard to tell a leak from simple condensation. But early detection is a must, because a leak left unattended can do a massive amount of damage in a short period of time.

These days, most boats are built with cored decks: an upper and lower fiberglass skin sandwiching a core material in the middle, such as plywood, balsa or plastic foam. Deck fittings, ports and hatches are installed by cutting openings in this core and mounting the hardware with sealant and screws or bolts.

When the sealant fails – and it always does – water starts leaking into the core, which can rot the wood or break the bonds between the core and the fiberglass. The result is, a spongy deck and a boat that is worth considerably less.

If you feel that spring in your deck, get on the problem immediately. If not, you can check for leaks by removing a fastener or even a port or hatch. If you can see exposed core, it's time to start removing the core around the opening or fastening and sealing it with epoxy filler. The fastener can then be replaced, screwed though the epoxy – a watertight solution.

Remember that by the time a leak starts dripping, it has already started to do real damage.

NEGLECTED ENGINE SYSTEMS

Most boaters will do routine engine maintenance this spring, but there are some steps you can add to the process to address engine systems that often get neglected – and perhaps prevent problems later.

If you have an impeller-style cooling water pump, remove the impeller and check for cracked or missing vanes (replacing the impeller annually is a good idea). While you have it out, check the impeller housing for any undue wear. Sucking up sand and sediment through the cooling water can erode the pump housing and reduce pumping efficiency.

Another overlooked area is the exhaust manifold and system. The exterior of these manifolds can appear fine while hiding extreme internal corrosion. If your manifold has any pipe plugs sealing off passages, you might want to pull one or two to check the internal condition. Removing the exhaust hose from the riser outlet is another way of checking.

On some boats, the ice box or the shower drains into the bilge. This is a sure source of unwanted odors. Install a sump of some sort to capture this water before it ends up in the bilge.While you're at it, check the condition of the rubber exhaust hoses. A momentary interruption to the flow of water through a manifold can cause damage to those rubber hoses, which are designed to be cooled by the water injected into them.

One area often overlooked on boats with outdrives is the rubber boot around the drive, where it is attached to the transom. Any damage – rodents looking for a warm winter home sometimes chew on it – can let water right into the boat.

While you are at it, check the lower unit oil and replace it. If it looks like coffee with water mixed in, you probably have a water leak.

HIDDEN COMPARTMENTS

The inside of a winterized boat – often shrink wrapped or covered with a tarp – can be a fertile breeding ground for mold. Inadequate ventilation increases humidity and helps fuel the spread of mold and mildew spores – and they can get into the myriad of hidden spaces on your boat.

Mold is unhealthy, and so you want to catch it early by inspecting places you don't usually see.

If you find mold, the best approach is remediation, which on a boat, means sealing up sources of leaking water and then killing the active mold colonies by disinfecting and cleaning the affected surfaces. You must be sure to wear appropriate personal protection while doing this: gloves, eye protection and a respirator rated at N-95 or above.

One chemical often used for killing the mold is common household chlorine bleach (mix no more than one cup of bleach to each gallon of water). Surfaces are wiped down or scrubbed with the bleach solution and then rinsed with water and dried.

You can also use one of the numerous products sold for this purpose, which contain chemicals to kill the mold, remove stains and prevent regrowth. One I have used is called Mold Avenger, which comes in a spray bottle. Prior to use, water is added to the bottle to dissolve the powder. After mixing, I sprayed the solution on all the affected surfaces. After letting it set for an hour, I scrubbed the surfaces to clean up the mold residue and stains. It worked well.

Mildew removal is a less toxic, but no less time consuming, process. I've had good luck with products by 3M and Star Brite, including 3M's Scotch Guard Water Repellant with a mildew blocker. This is good for treating boat canvas and other onboard fabrics.

Thanks largely to hurricanes Katrina and Rita, there is quite a bit of information about mold remediation available on the Internet. While much of it is focused on mold in homes, the information is equally useful in removing mold in boats. The Environmental Protection Agency has two booklets, "A Brief Guide to Mold, Moisture, and Your Home" and "Mold Remediation in Schools and Commercial Buildings" available for free on the EPA website. The Centers for Disease Control also has a section of their website devoted to mold, its effects and remediation.