How Do You Fight Mold and Mildew?

Over the weekend, docks in the Bay Area were bustling with activity, as we were blessed by two splendid, sunny days, after enduring weeks of almost nonstop rainstorms. Not surprisingly, one of the dominant topics of conversation heard between slip neighbors was, "How are you coping with mold and mildew?"

As one old salt noted, "Hey, it’s a boat. You’re always going to get some of that."

But some boats suffer far fewer mold and mildew problems than others due to the steps their owners take to battle this inevitable nuisance. Many longtime boat owners will tell you that ventilation is key, but when storm conditions bring horizontal rainfall driven by 40-knot winds, leaving hatches cracked open isn’t always an option.

Some boat owners swear by dehumidifiers or low-amperage air-circulation devices. But even so, mold and mildew can creep into isolated areas, so periodic cleaning will still be necessary. What to use? Many longtime cruisers swear by plain old vinegar, as it is mild yet effective, nontoxic and available everywhere. 

For many sailors the fallback when combating really nasty areas is often to hit it with a bleach solution (i.e. 10:1 water to bleach), the downside being that bleach fumes belowdecks are never pleasant, and potentially could be harmful to lungs, skin and eyes. 

A quick Internet search led us to a variety of other techniques that are nontoxic:
• baking soda (small amount in water)
• isopropyl alcohol (regular "rubbing" alcohol, sprayed or rubbed on the surface)
• hydrogen peroxide (use full strength, but sparingly; may bleach fabrics)
• tea tree oil (use 2:1 with water; works great and eliminates moldy smell)
• grapefruit extract (although not so easy to find, it works well and protects against future growth; safe around children)

That’s our ‘two cents’ on the subject, but if you’ve got additional thoughts on this icky and annoying topic, we’d love to hear from you. What have you found to be the most effective weapon against mold and mildew?