Fall and Winter Boat Care on the Coastal Bend
October is here, and now is the time to get your boat ready for the cooler months. Winter on the Coastal Bend isn't Michigan. Most days you can still get out on the bay, and plenty of boat owners do their best fishing between December and February. But winter here still does damage. Cold fronts swing the temperature 30 degrees overnight, the humidity never really leaves, and every few years a hard freeze catches people off guard.
The bigger risk for most boats isn't the cold. It's sitting. A boat that runs every weekend in July can sit for weeks at a time once the northers start blowing, and fuel, batteries, and seals don't like sitting.
So the first question is simple: are you going to keep using your boat this fall and winter, or park it until spring? The prep is different for each. Below, we break it down by system, with a short "Still running it" and "Parking it" list for each one.
Your 4-Stroke Outboard
Modern 4-strokes are reliable, but they're also the most expensive thing on your boat to neglect. Used engine oil holds moisture and acidic combustion byproducts, and letting it sit in the engine for months is one of the easiest ways to shorten its life. (For more on the basics, see our guide to 4-stroke outboard maintenance.)
Still running it:
Stay on your hour-based service schedule. Winter hours count the same as summer hours.
Flush with fresh water after every trip, even if the water feels cold.
Give the engine time to warm up on cold mornings before putting it under load.
Watch your tell-tale stream. A weak stream can mean a worn water pump impeller or a stuck thermostat.
Run it at least every couple of weeks if it's going to sit between trips.
Parking it:
Change the engine oil and filter before storage, not after. You want clean oil sitting in the engine all winter.
Change the lower unit gear oil. If the old oil comes out milky, water is getting past a seal, and that needs attention before spring.
Fog the engine or follow your manufacturer's storage procedure to protect internal parts from corrosion.
Replace the fuel/water separator filter.
Grease every fitting, including the steering and tilt tube.
Check the sacrificial anodes and replace any that are worn down.
Leave the motor trimmed all the way down so the cooling passages drain. Water trapped in a tilted-up motor can crack parts in a hard freeze.
Gasoline
Most pump gas is E10, which is 10% ethanol, and ethanol pulls moisture out of the air. On the Texas coast, there's always moisture in the air. Given enough time, that water can separate out and settle at the bottom of your tank as a layer of water and ethanol, right where the fuel pickup sits. That's called phase separation, and it's a common cause of hard starts, rough running, and fuel system repairs in the spring.
Still running it:
Buy fuel from a busy station so it's fresh, and burn through a tank in a reasonable amount of time.
Use ethanol-free fuel where you can find it.
Check the fuel/water separator bowl for water, especially after a stretch of cool, damp weather.
Parking it:
Add a marine fuel stabilizer, then run the engine for 10 to 15 minutes so treated fuel reaches the whole system.
Store the tank nearly full, leaving a little room for expansion. A full tank has less air space, so less moisture condenses inside it.
Don't store it half full. Temperature swings between warm afternoons and cold nights pull moist air in and out through the vent all winter.
The Hull, Bilge, and Trailer
Salt doesn't take the winter off. Anything left on the boat keeps working on the gel coat, the hardware, and the trailer, whether the boat moves or not. (Our post on what salt water does to your boat over time covers this in more detail.)
Still running it:
Keep up the fresh water rinse after every trip, including the trailer.
Watch the tides. Strong northers push water out of the bays and can leave flats and channels much shallower than you're used to.
Inspect the hull and lower unit for dings from winter groundings before small damage turns into big damage.
Parking it:
Wash the boat thoroughly and apply a coat of wax to protect the gel coat.
Look for cracks, blisters, or soft spots in the deck and hull, and get them checked before spring.
Clean and dry the bilge. Drain livewells, baitwells, and washdown lines so nothing sits in them all winter.
If the boat stays on a trailer, pull the drain plug so rain can drain out, raise the bow slightly, and leave a note on the helm to put the plug back in.
Use a breathable cover with support poles so water doesn't pool, and leave some ventilation to keep mildew out of the upholstery and storage compartments.
Service the trailer: repack or check the wheel bearings, look at the tires for dry rot, and test the lights and brakes.
Batteries
Dead batteries are the number one reason boats don't start in the spring. A battery slowly drains even when nothing is turned on, and small draws from bilge pumps, stereos, and electronics speed that up. Cold weather also cuts how much cranking power a battery can deliver.
Still running it:
Recharge your batteries after every trip so they don't sit discharged, and plug in the charger the day before you head out to make sure you start at full charge.
Clean the terminals and check for corrosion, loose cables, and swollen or cracked cases.
Have your starting and trolling motor batteries load tested. A battery that barely made it through summer often fails on the first cold morning.
Parking it:
Charge every battery fully, then remove it from the boat.
Store batteries in a cool, dry, temperature-controlled space. Heat and freezes are both hard on batteries.
Top them off with a charge every month or two over the winter so they don't drain too low.
Lithium batteries have their own storage and charging rules, so follow the manufacturer's guidance.
Pro Tip: Don't want to haul batteries home? The Boat Werx team will pull, test, store, and reinstall them for you.
Electronics
GPS units, fish finders, radios, and switch panels live in a salty, humid environment, and corrosion at a single connector can take out a whole system. Winter is the best time to get ahead of it.
Still running it:
Keep a cover on your displays when the boat isn't in use.
Test your VHF radio, navigation lights, and bilge pump and float switch. Winter days are shorter, and you're more likely to be running at dawn or dusk.
Wipe salt spray off screens and connectors after every trip.
Parking it:
Remove displays that are designed to come off and store them indoors, or cover them well.
Inspect connectors and wiring for green corrosion, and protect connections with dielectric grease.
Update the software on your chartplotter and fish finder. The off-season is the easy time to do it.
Clean the transducer face and check its mounting for cracks or loose hardware.
Everything Else
A few more items that apply to every boat owner this time of year.
Hard freeze warnings: They don't come often here, but when one is forecast, drain livewell and baitwell pumps, washdown lines, and any freshwater system, and make sure the motor is trimmed all the way down.
Cold water safety: Bay water temperatures drop well below air temperatures in winter, and a fall overboard is far more dangerous. Wear your life jacket, dress in layers, and tell someone where you're going and when you'll be back.
Safety gear: Check flare expiration dates, confirm your fire extinguisher is charged, and make sure life jackets are in good shape.
Pests: Stored boats attract rodents, wasps, and mud daubers. Remove all food and bait, and check vents and compartments before your first spring start.
Upholstery and canvas: Clean and treat vinyl, and let everything dry fully before covering to prevent mildew.
Paperwork: Check your registration renewal date, and ask your insurance company whether your policy has any storage or lay-up terms.
Let the Boat Werx Team Handle It
Everything on this list is something Boat Werx of Texas Service does every day. Whether you're fishing all winter or parking your boat until spring, our team can take care of it for you.
Fall and winter prep for boats going into storage: oil and filter, lower unit, fuel stabilizer and filters, fogging, grease, anodes, and battery care, all in one visit.
Service for boats that keep running: hour-based outboard service, water pump and impeller work, and a full inspection before winter fronts roll in.
Batteries and electronics: winter battery storage (we pull, test, store, and reinstall them), load testing, charging systems, wiring and connector repair, and electronics installs and upgrades.
Hull and trailer: inspection, cleaning, bearings, tires, lights, and brakes.
Spring startup: when the weather warms up, we'll get your boat back on the water without the surprises.
Here's a tip: the off-season is the best time to book service. When spring hits, every shop on the coast gets busy at once. Get your boat in now and it'll be ready when you are.
We have two Aransas Pass locations to make drop-off easy:
Redfish Bay Marina: 322 Huff St, Aransas Pass, TX
Boat Werx Service Location: 2471 TX-35 Bypass, Aransas Pass, TX
Call (281) 559-BOAT (2628) or contact us through the website to schedule your fall and winter service.