In-Water Cleaning Restrictions: Where It's Banned and Why
By Tomas Iglesias, Yacht service diver, South Florida. Reviewed by Amanda McCallister, editor.
Hull & Bottom Cleaning | Marine Salvage & Recovery Last spring I was swapping a bronze prop on a 58-foot Sea Ray at the Lauderdale Marine Center when the owner asked if I could do a bottom wipe while she was still hooked to the dock. No problem here, I said. Back in San Diego, where he berths most of the year, that same job would land him a fine and me a yanked permit. That's how fast the rules flip-flop. Fifteen years of diving on props, hulls, and running gear from Jupiter to Key West, and I've learned that in-water hull cleaning is legal, illegal, or a gray area depending on exactly where you drop the anchor. This post is the compliance run-through I wish someone gave me when I started. Every state, and a lot of counties, have a different take. Some outright ban it. Some require a closed-loop system. Some just look the other way until a neighbor complains. You can't assume - you have to check.
Where the rules are tightest
California is the big one. The state's Marine Invasive Species Program plus local NPDES permits have pushed most marinas in San Diego Bay and Long Beach to ban or restrict in-water cleaning. Lake Tahoe goes further - copper-based antifouling paint is prohibited, and any hull cleaning while the boat is in the lake is a ticket. Out east, Maryland's Clean Marina Program requires you to collect wash water at some public marinas in Annapolis and Baltimore. Washington state is working its way there, too, and I've seen reports from New Zealand and Norway that are even stricter. Back home in Florida, we're lucky - but not forever. A few counties, like Brevard, have started to fine boats that ground a haul-out. It's a patchwork. Call it one big moving target.
Why the rules exist: copper, zinc, and the food web
The reason is simple: antifouling bottoms are laced with copper and zinc. When I scrub a hull, I release a cloud of those metals. In warm Florida water, a 50-foot boat can shed a few grams of copper per cleaning - sounds tiny, but it settles into the sediment and sticks around. Concentrations in marina mud often exceed 400 parts per million. Studies have linked that to altered growth in oysters and neurological damage in juvenile fish. The EPA's marine water quality criterion for copper is 3.1 parts per billion. That's a fraction of what you'll find right under a dirty hull. And here's the digression: a guy once told me he was just 'rinsing the slime' and the copper didn't come off. That's baloney. Even a soft brush lifts a layer of paint, and with it, the toxic pigments. That's the chemical footprint the regulators are chasing.
How we work around the rules
If you're in a state that allows it, you still want to be smart. In Florida, we use low-speed brushes and a wet-vac system to catch the loose paint. Some operators carry a portable closed-loop unit that sucks up the water, filters it, and pumps it back. You can rent those by the day - the rate varies by marina, but it's a line item you can ask for. But the cleaner approach is to switch coatings. Biofouling-release paints from companies like Sea Hawk and Pettit don't leach biocides. Once they're applied, you can wipe the bottom with a light pad underwater and you're not violating copper restrictions. The trade-off is they can be pricier and less durable. Honestly, the smartest workaround is scheduling your haul-out. Let the diver do the scraping while the boat is on the hard. Then, between hauls, we stick to gentle wipes if it's legal. That saves you from environmental guilt and a nasty-gram from the marina.
What boaters need to know to stay compliant
Start with a phone call. Call the marina office or the local harbor master and ask about hull cleaning rules. If they say it's allowed, ask if there's a permit or a treatment requirement. Some places have a 'no visible paint in the water' rule. Others want you to use an approved cleaner. And if you're in a state with a marine invasive species program, they may ask for proof of a hull inspection or a record of last haul-out. Document everything. Take a photo of the permit. Write down the date, time, and place of every cleaning. I keep a waterproof log on board. It sounds like overkill, but when a neighbor files a complaint, you'll have receipts. The bottom line: in-water hull cleaning is not something you can take for granted anymore. The rules are tightening, and the ones who get burned are the first-timers who didn't ask. So ask. And if you're in South Florida, you'll likely be fine - but always confirm the local status first.
Frequently Asked Questions
Is in-water hull cleaning illegal in California? Not statewide, but most marinas in places like San Diego Bay and Long Beach now ban it unless you use a closed-loop system or have a special permit. Lake Tahoe is an outright no-go for any in-water cleaning, and copper-based antifouling paint is prohibited there. What is a closed-loop hull cleaning system? It's a portable unit that sucks up the water and paint debris around the hull, filters out copper, zinc, and other biocides, then pumps the cleaned water back overboard. Many strict marinas require divers to use one - or to have the boat hauled out instead. Can I clean my own hull with a brush in Florida? In most of Florida, yes, but not everywhere. Some counties and marine districts have started to enforce antipollution rules that target paint chips and metal discharge. Always check with the local marina or harbor master before you drag a brush across the bottom. Are copper-free paints the solution? They help. Biocide-free or foul-release coatings let you wipe the hull in the water without releasing copper, but they're not a free pass everywhere - a few places restrict any in-water cleaning regardless of coating. And some copper-free paints still use zinc or other metals, so check the label.