California Anti Fouling Studies and Publications
NOAA Coastal Services Center
"Overall, water temperature and time since the last cleaning were primary predictors of fouling growth. The Best Management Practices (BMPs) of using a gentler tool and cleaning frequently were the best practices for extending coating life and compensating for higher application and cleaning costs. Cleaning more frequently prevents fouling growth from accumulating to high levels. In turn, this allows divers to use less aggressive cleaning tools, spend less time cleaning, and exert less effort. Frequent cleaning may thus be expected to extend the life of the coating.
Sea Grant - Making a Choice
Boaters can help underwater hull cleaners, marinas and boatyards control costs, promote a healthy boating environment and encourage abundant marine life by considering environmental factors when selecting an antifouling strategy. More information is available in our publication, “Boating Pollution Economics & Impacts.” These tips may reduce environmental impacts:
Go boating often to slow fouling growth.
Hire an underwater hull cleaner who uses best management practices. (See our publication, “Selecting Underwater & Topside Maintenance Services for Your Boat.”)
Clean hull often to prevent hard growth and reduce scrubbing and toxicant release.
Select a paint that does not require caustic solvents and releases little or no pollutants.
Use a hard, less toxic or non-toxic paint and wipe hull often to remove soft growth.
Some thoughts of my own:
In Ventura County where I operate, monthly cleanings are my preferred schedule. This is true for both types of paint and provides a balanced approach to proper maintenance over the effective lifetime of the paint. The majority of boats I service sit in place for much longer periods of time than they do underway. The slime and algae that accumulate will to some degree come off when underway – at the bow, waterlines and transoms where oxygenated water is churning. Below these areas and out of sight of the typical boat owner, the slick brown algae remains.
Keep in mind also that a boats running gear - the knot meters, through holes, intake screens, shafts, propellers, rudders, trims etc… most often do not have antifouling paint applied. When it is applied to metal running gear it more often than not flakes off or quickly becomes ineffective. The reason for this is the copper in anti fouling paint reacts with other metals. I see only a very small percentage of properly undercoated metal.
Definition of VOC: VOLATILE ORGANIC COMPOUND is any volatile compound which contains the element carbon, excluding methane, carbon dioxide, carbon monoxide, carbonic acid, metallic carbides or carbonates, ammonium carbonate, and exempt compounds.