Spring Launch Smell Check

How to Make Your Boat Look (and Smell) Shipshape on the Great Lakes.

Published: Friday, May 8, 2026 9:00 am
By: Captain Brett Tyren of CAVU Marine and Midwest Yacht Sales

It’s that time of year again! Boating season is upon us, the shrink wrap is coming off, and your boat is about to make its first impression of the season. And just like people…boats can have issues.

After many years of delivering and managing vessels, both commercial and private, I can tell you this: odor kills deals. As a retired surveyor, I’ve seen plenty of boats sit unsold not because of price or layout, but because of poor mechanical maintenance and interior smells that just wouldn’t quit. The good news? You can fix this—starting now.

Step One: Start a Logbook (Yes, Like Pilots Do)

Before you grab the cleaners, grab a notebook. A cleaning and maintenance logbook, similar to those used in aviation, helps keep you consistent and accountable, as well as adds real value when it’s time to sell. Buyers love it. Surveyors love it. And it removes a whole lot of guesswork from the process. No seal of approval required, just good habits.

Winter Storage: Let Your Boat Breathe

If your boat is stored outside under shrink wrap, be sure to invest in a zippered door, and add a few extra vents. Why it matters:

Doors let you access the boat on mild winter days (early cleaning = less spring panic)
Vents reduce moisture buildup
Crack a porthole when possible so the interior can respire (boats need fresh air too)

Interior Odors: Where They Start (and How to Stop Them)

Air Conditioning Units

If your boat has A/C, be sure to clean the vacuum filters and coils annually. Clean coils means less work for the unit and better airflow. Not to mention that mold and mildew love 55–60% humidity — this is prime real estate for growth. After cleaning these items, lightly spray the area with Crisp Linen Lyson; this kills growth, dissipates quickly (no “grandma’s closet” vibe), and is client-approved. You’ll see this product come up again. There’s a reason.

Below Decks: Mold’s Favorite Hangout

Temperature differences between air and water make below‑deck spaces a mold paradise. Best practices include:

Cleaning these areas often.
Spraying lightly with Crisp Linen Lysol and wiping down.
Leaving hatches open when possible for ventilation. Pro tip: Remember which hatches are open (broken legs ruin weekends), and never store soft goods below decks.

Heads & Holding Tanks: The Topic Nobody Loves (But Everyone Needs)

Let’s be honest — nobody wants to fix the head. But here’s the rule: You either fix it because you use it…
or you fix it because you didn’t. After Every Pump‑Out, be sure to use Aqua Chem or a similar biodegradable product/ Pour the proper amount into the toilet bowl and flush, NOT into the deck fitting, as it won’t reach the tank.

Don’t Forget the Shower Sump

Grey water smells can rival black tank odors. Do this:

Rinse the Aqua Chem bottle in the sink
Pour a small amount down the shower drain
CAUTION: The blue color WILL STAIN towels, rugs, carpeting, etc!

This stabilizes skin cells, hair, and organic buildup in the sump tank and pump. A bonus is that the sump flushes clean during normal showers. You can also consider changing the charcoal head vent filter every season or two.

The Olive Oil Trick (Yes, Really)

Before leaving the boat for any extended time:

Turn off the head system
Dry the bowl
Add 1 ounce of olive oil to the bowl
(Not corn oil — it spoils faster and doesn’t work as well)

Why it works:

Keeps the bowl gasket soft and sealed
Prevents air leaks that cause vacu‑flush pumps to run nonstop
Lubricates tank floats and sending units
Helps solids move more freely during pump‑out

It’s cheap, effective, and shockingly underused.

Soft Goods & Final Cabin Freshening

As you exit the cabin, be sure to lightly spray the air and soft goods with Crisp Linen Lysol before closing the hatch. Avoid heavy fragrances, as buyers and brokers will “smell through” them every time. Clean beats scented. Always.

Exterior Cleaning: Simple, Effective, No Nonsense

For General Wash: Add any biodegradable boat soap to 1 cup of white vinegar and scrub away.

For Non‑Skid & Fishing Decks: To help against dirt, bloody, or heavy grime, sprinkle powdered OxyClean and scrub with a soft-bristle brush (hard bristles don’t reach the tiny grooves. And be careful, it’s slippery!

For Synthetic & Natural Teak Decking: Need to get out a difficult red wine stain? K2R may be your new best friend.

Windows: Night Operators, This One’s for You

Dirty windows at night are a special kind of misery. The secret? Wash in the early morning, never in direct sunlight. Wash with the same vinegar solution, and while still wet spray with Sprayway Window Cleaner and squeegee. Do the final buff with a lint-free towel. Result? Crystal‑clear views during night crossings on the Great Lakes, or the Gulf.

Engine Spaces: Clean Boats Catch Problems Early

A clean engine room helps you spot leaks early, prevent big problems later, and makes troubleshooting faster. Best practices:

Place white diapers or absorbent pads under engines.
Keep a small trash bin for towels and debris.
Empty weekly — organic odors don’t care if it’s lake water.

While on the hard:

Pull the drain plug.
Catch engine room runoff in a 5‑gallon bucket.
Dispose of cleaning agents and runoff properly (your marina will thank you).

Tools worth keeping onboard include toilet brushes, bottle brushes, and a flashlight. They make sea strainer cleaning faster and easier—and you’ll actually do it.