What to check when your boat comes out of the water

Bellows and the gimbal area (sterndrives)

Look at the drive bellows, the exhaust bellows, and on Alpha drives the shift-cable bellows, for cracking or dry rot. Cracked bellows let water into the gimbal bearing and U-joints, which is a far more expensive repair than the bellows themselves, so this is one of the more important checks at every haul-out. See sterndrive repair if anything looks questionable.

Anodes

Check every anode: the drive bullet or anode plate, trim tab, prop nut, shaft collar, rudder and transom plate if fitted. Replace at around fifty percent erosion. Freshwater like Lake St. Clair calls for magnesium anodes; if anodes look crusted or passivated rather than actually eroding, that's a sign of the wrong metal or a bonding problem rather than the anode doing its job. Anodes disappearing unusually fast, on the other hand, points to stray current rather than normal protection. See marine electrical if you suspect either.

Prop and running gear

Check the prop for dings, bent blades or fishing line wrapped at the hub. On shaft-driven boats, check the cutless bearing for play by trying to wiggle the shaft in it; noticeable movement or a flat-worn groove means it needs replacing. Look at the shaft itself for signs of bending or pitting.

Gear lube

On a sterndrive or outboard, check the gear lube for a milky or cloudy look rather than clear oil. Milky lube means water has gotten past a seal somewhere in the lower unit or drive, and it's worth investigating before it causes more damage over the winter or before next season's first run.

Thru-hulls and seacocks

Exercise every seacock to make sure it isn't seized, and take a look at the thru-hull fittings themselves for cracking or corrosion. A seized seacock is a problem you want to find at haul-out, not the next time you actually need to close one in a hurry.

Hull and bottom

Look over the bottom paint and gelcoat for blisters, cracks or unusual soft spots. Minor bottom paint wear is normal; anything that looks like a soft or spongy spot in the hull itself is worth a closer look before it's covered back up for the winter.

Exhaust manifolds and risers (gas inboards and sterndrives)

Rust staining, blistered paint or visible corrosion on the exhaust manifolds and risers is worth flagging. On raw-cooled gas engines, a corroded riser can eventually let water back into the cylinders, which is a serious failure, so catching corrosion early while the boat's out is worth the extra minute.

Steering and controls

Turn the wheel through its full range and work the shifter and throttle by hand to feel for binding. Anything stiff or rough is easier to deal with now than after it's frozen solid over the winter.

Belts and hoses

With the engine accessible and not running, look over the belts for glazing, fraying or cracking, and check hose clamps and hoses for chafe, soft spots or weeping. A belt or hose that's marginal in September is a much easier fix on the hard than a failure out on the water next season.

Engine mounts and general cleanliness

Check engine mounts for obvious cracking or excessive movement, and take the opportunity to look over the bilge generally while it's accessible and (hopefully) dry. Oil sheen, a rusty smell, or debris in the bilge are all worth noting even if none of them are urgent on their own.

What to do with what you find

Write down or photograph anything that looks off. None of it needs to be fixed immediately in most cases, but it's the kind of thing worth addressing over the winter rather than discovering again at spring launch under time pressure. See boat diagnostics for a second opinion, or roll findings straight into your winterization or spring commissioning visit.