Washington State bans copper bottom paint

[Faris]

So we should ban things based on risk. OK.

Nope. I'm saying that we should be responsible and not do things that are correlated with harmful effects.

Here's something about physical sciences that the anti-environment crowd tends to forget/misunderstand/ignore. There is very little in life sciences that can be proven. All we know is what we observe. For example, we don't know that smoking causes cancer. All we know is that there is a strong statistical correlation between smoking and some forms of cancer. So, since we can't prove the connection, do we deem smoking safe?

This is a bit like the global climate change issue. As a side note, let me go out on a limb and guess that those who are coming down on the side of allowing copper paint are also among those who think that global warming and its causes are still controversial and that evolution is "just a theory".

Let's look at TBT-based paints. Would anyone argue that TBT-based paints are not harmful? Of course not. Yet, though they are more effective than copper, they have been outlawed to varying degrees in different places globally. Consider the policy in the UK. There, TBT is banned on boats smaller than 25m, but is still widely used on larger commercial vessels. So, is it responsible to use TBT? Probably not. Just because some vessels are allowed, does that mean that it should be OK for everyone?

Copper-based paints leech copper - that's how they work. Copper concentrations are high in marinas. High copper concentrations are associated with adverse effects on the ecosystem. My point in my previous post was that, even though we can't yet prove that the use of copper paints on recreational boats contributes enough to the problem to have adverse effects, why would we deliberately leech copper into the water either in the absence of such proof or, worse yet, purely on the basis that the law allows some people to do it?

Setting aside whether it is legal or not, banned here and not there, allowed for some and not others ... setting all that aside, it is still asinine and irresponsible. That is, if we know it is likely harmful, why would anyone of good conscious defend its use? Particularly when viable and less harmful alternatives exist? It makes no sense.

There is really no drawback to using alternatives aside from a slightly higher cost (which is likely to change as more states ban copper paints in more applications ... the copper-free paint I bought last year for $270 can be purchased for $160 today). It seems that most of the objections, claiming that they are less effective or don't last as long, are just knee-jerk responses by people who are against government regulation of any sort. Anyway, if this was purely a matter of choosing the most effective agent, we should just go back to using TBT. For that matter, why not just chlorinate the water in marinas and be done with the problem altogether?

But, it's not just a matter of effectiveness. We have to balance a number of concerns/factors - environmental, economical, etc. What makes this one a no-brainer is the fact that there is no loser to changing from copper-based paint. Paint manufacturers make and sell what people buy. So, there's no problem there. People who paint boats shouldn't care what kind of paint is used.

So, it seems that it just comes down to people complaining that it may cost them a few more dollars. That's just downright self-centered, and frankly, short-sighted. I'm betting that, in the next few years, we will come to realize that copper-free alternatives don't cost any more to maintain. Things that people don't think about are issues such as the fact that, for example, stripping a copper-based paint requires special handling of the debris (depending on local regulations). This handling raises the cost of that work by increasing labor. And labor is, by far, the biggest chunk of the cost of that job.

(By the way, I really don't know what special waste handling is required of copper-based paint. I'm just assuming that most municipalities place some restrictions on this and that those cost the boat-owner money. My only point there is that end-cost is not always so easily predictable.)

 

[JK_Boston_Catalina310]

Quick Response to Petersea

Petersea,

Basically, yes size matters. The EPA has precedents for looking at applying regulations based on the magnitude of the offender. With the CWA the first to be brought into compliance was the industrial discharges. Then the large municipal systems (based on gallons per day), then medium, then small, then construction sites and so on.

In this case the logic is a little in reverse. There are far more smaller boats (less then 65 feet) and the total surface area for those boats far exceeds that of the larger boats.

As to the super tanker, I would suspect they are not subject to this anyways because they are not registered in the State of Washington.

Trying to make regulations that can actually be enforced and that can practically be complied with is tough. Often there is give and take and I suspect that how some of these exemptions came into play.

I don't disagree that the government should lead by example or that this type of rule should apply to all. But that is not the world we live in. The government is one of the worst offenders of environmental regulations. And blanket applications of regulations is seldomly done in the world of lobbyists and litigation.

 

[fstbttms]

What makes this one a no-brainer is the fact that there is no loser to changing from copper-based paint. Paint manufacturers make and sell what people buy. So, there's no problem there. People who paint boats shouldn't care what kind of paint is used.

Don't get me wrong, brother, because you have made the most thoughtful, salient argument yet in this thread. But FYI- in the case of SB 623, the paint manufacturers want to amend the bill to allow what they are calling "low-release rate" anti fouling paints. Copper based paints with lower copper content and lower copper release rates. Some of these products are on the market now and have been for years. They want to essentially change the very nature of the bill to allow copper to continue to be used. Why? Because the paint manufacturers buy copper on futures. They are invested in copper for years to come and do not want to have to unload it or, God-forbid, eat it. They claim that California's water quality goals can still be met while using these low-release paints. But that's what you'd expect them to say, they're in the business of selling copper (for now.)

 

[petersea]

Faris
" I don't use copper paint, not because they are banned, but because it is the responsible thing to do. Does it cost me more? Yup, but that is not the issue. If I can't afford it, I don't get to go boating. The pressure on my pocketbook does not give me the right to be less responsible.

And, frankly it's not much more expensive - a drop in the bucket for my annual maintenance budget. I get about two years out of a recoat. The cost of the paint is a tiny part of the cost of a hull job. My friends who use copper-based paints get about two years as well. After two years, the result is about the same. It looks like you can stretch copper paint a little longer, but that's hardly the issue. "


Faris, could you be more detailed on the type of bottom paint you are using ?? brand ? cost etc ? do you and how often do you clean the bottom ? etc etc. I would appreciate any personal thought you have as to if it is better, worse or about the same as copper based paint and why ??
What were the original number of coats required and time between recoats(how many coats do you put on when recoating). Maybe tell us what type and size boat you have and a brief description of you sailing ? (day sailer or cruiser ?) Just interested to get some "real world" results.

Thanks

 

[Faris]

But FYI- in the case of SB 623, the paint manufacturers want to amend the bill to allow what they are calling "low-release rate" anti fouling paints. [...] Why? Because the paint manufacturers buy copper on futures.

Thanks for this. Yes, undoubtedly there are some short-term losers. But, for each dollar lost by one industry is a dollar gained by another.

One thing that's interesting, though, is that consumers have shown repeatedly that they are willing to pay slightly more for products with slightly lower performance, if they believe those products to be healthier or better for the environment. People pay more for organic food, hybrid cars, fair-trade clothing, etc.

In the short term, smart paint manufacturers can profit from these sorts of regulations by selling these as specialty paints with a higher profit margin because some consumers cannot use the less-expensive alternative. Companies that don't transition away from copper and TBT do so at their own peril. They are betting that the people will not side with the environment in the long term. Those companies that position themselves well by developing effective and inexpensive environmentally friendly products will make a killing.

The bottom line is that, if we believe in capitalism, we believe that if there is demand for a product, someone will make and sell it for what people believe it is worth - no more, no less.

 

[Stu Jackson]

OK, what's the alternative?

I agree with Pete's questions, two above. What are the alternatives that those of you who use it are? Please, let us know.

Can you put it on top of say Trinidad, or do you have to strip what's there?

I sure would feel stiffed if all I got for more money was less protection, especially if it was just less copper 'cuz the paint companies bought it and simply want to get rid of it.

 

[Faris]

Faris, could you be more detailed on the type of bottom paint you are using ?? brand ? cost etc ? do you and how often do you clean the bottom ? etc etc.

I don't have a ton of experience with it since I've only applied twice now. There are a few people here that have a bunch more experience with bottom paints than I do. Here's what I do know from personal experience though:

I had a 24-foot fiberglass sailboat. She was moored in fresh water (near the locks) and sailed almost every week in salt water for a day (on average), plus a week or two once or twice in the summer. So, right away, that helps regardless of the paint. I pulled her out each year to inspect, and repainted the bottom twice while I had her. The first time I used Interlux Pacifica Plus about 2 1/2 years ago. Before that, she had some copper-based paint and it had been 2 years since her last paint. Not much had to be done to the hull (it was pretty clean), and I could have painted right over the copper, but I chose to have it removed before repainting.

Two years later (just recently and before I sold her), I pulled her out again. The bottom looked slightly better than in did two years earlier, but that is pretty subjective. It was pretty clean both times. However, the paint looked like it might have been in better condition. Hard to say, but it was certainly no worse.

Each time I repainted, I just used a whole gallon and got as much out if it as I could. I paid $280 two years ago, and $160 this time.

I have three friends with very similar situations. One has a 21 foot sailboat similarly moored and sailed (in fresh/salt water), and the other has a 27 foot sailboat moored on the saltwater side of the locks, but spends a few weeks in fresh water each year to help keep his hull clean. The both have always used copper-based paints. My third friend has a 38 foot sailboat moored in saltwater, but doesn't go out but maybe once a month or so, and almost never into fresh water. He applied Pacifica Plus at almost the exact same time as I did two years ago.

My friend who used copper-based paint and who remains moored in saltwater, after two years, needed some scraping that none of the rest of us needed. All of the rest of us saw pretty similar results after about two years. The boat we would expect to be in the worst shape (the 38 foot boat moored in saltwater and who rarely moves), was no worse than anyone else, and was actually better off than the friend moored in the same marina with copper-based paint on his hull.

My conclusion: Living near the locks is a huge benefit. Being able to spend significant time in each water type seems to have a strong effect on keeping the hull clean. And, Pacifica Plus seems to perform as well or better than whatever copper-based paints were in use on the other two boats. This "case study" is too small and not well-controlled to say anything conclusive about Pacific Plus, but I have seen it work great for two years on two different boats in two different conditions, while the copper-based paints did not perform any better, and in at least one case, seemed to underperform.

And, with the price coming down to $160, and expecting to pay about $80 for an inexpensive copper-based paint, the last time I applied it, it cost me about $80 to stop leeching copper into the water for two years - about $3 a month out of my $100 per month maintenance budget. I expect the price to come down to about $120 by the next time I need to buy it, which equates to about $1.50 per month over copper-based paint.

 

[fstbttms]

Bear in mind, those of you who are in moderate or high fouling regions (like California) that fouling rates in the Puget Sound region are significantly lower than they are here. So the performance one boater experiences with a particular product in Seattle may be vastly different than what another experiences with the same product in San Francisco or San Diego. YMMV. FYI.

 

[Joe]

So are you saying that less air pollution causes homosexuality?

No..... I didn't say anything about homosexuality.... I did say that cleaner air quality is good for all of us... and I credit the EPA for that... at least in California.

 

[jibes138]

My objection to this whole situation is the selective manner that the EPA decides to implement change that has little beneficial impact on the environment but causes widespread impact to our economy and lives. It is not based on a pareto chart of highest to lowest environmental impact, seems to be based on easiest to implement and votes.
Since marinas are already contaminated, how will this improve things unless they are all dredged and the waste "disposed of." On land as a society we have decided to designate certain land areas we are willing to severely pollute so as not to pollute the rest of the land too much. These are called landfills. Far more pollution in landfills than any of these marinas could possibly imagine. This pollution is leaching into ground water, running off into rivers and streams. Then we start trash to energy plants and start creating toxic ash, where do you think that goes?
I have the cleanest most amazing storm water ditches in the whole wide world yet I drive by hundreds of miles of storm water ditches that are completely unmanaged. So where is the cost benefit and environmental benefit analysis of these regulations? Will the clams suddenly return to the marinas, how many years will the environment in marinas be restored to original condition? How about the chemicals in pressure treated pilings, is that the next regulation? A very good case can be made in this whole matter to the real problem, that being geometric population growth that is unsustainable. Yet no one will go down that path for fear of offending certain special interest groups.
Are coppper paints harmful to living creatures, yes, thats why they kill barnacles and what they are designed to do. So suddenly we wake up and say "the poor barnacles?" Amazing. It will only be a matter of time until the "new" paint is also deemed unacceptable, where is the data showing the environmental impact of the new stuff? Does it still kill barnacles? Guess I'll go back to my pulled pork dinner and think about the hog effluent washing into the neuse, but hey, people have to eat.

 

[KD3PC]

People pay more for organic food, hybrid cars, fair-trade clothing, etc.

SOME people may pay more for these things...

others of us have SEEN what "organic food" really is....the stall at the farmers market in my town that "Sells" organic food simply pours wholesale vegetables in to a quaint looking container. Certainly the Feds have done NOTHING to define "organic"

Hybrids are good till you need to change the batteries, where is all that "green" now...and I love those with plug ins who don't realize that all that "cheap electric" is made with coal or oil in most cases..nothing is FREE.

I don't buy clothes, except second hand, any more. Retired now.

So this statement is patently false.

 

[JK_Boston_Catalina310]

SOME people may pay more for these things...

others of us have SEEN what "organic food" really is....the stall at the farmers market in my town that "Sells" organic food simply pours wholesale vegetables in to a quaint looking container. Certainly the Feds have done NOTHING to define "organic"

Hybrids are good till you need to change the batteries, where is all that "green" now...and I love those with plug ins who don't realize that all that "cheap electric" is made with coal or oil in most cases..nothing is FREE.

I don't buy clothes, except second hand, any more. Retired now.

So this statement is patently false.

Do you even understand was "patently" or "false" means?

How does anything you offered disprove what Faris offered?

In fact, your statements only prove to support his statements. He said "people" not "all people", not "everyone". You acknowledge that "some" people do more for "green" products. You just questioned if they are truly "green".

 

[JK_Boston_Catalina310]

My objection to this whole situation is the selective manner that the EPA decides to implement change that has little beneficial impact on the environment but causes widespread impact to our economy and lives. It is not based on a pareto chart of highest to lowest environmental impact, seems to be based on easiest to implement and votes.

Yup, the EPA does do the easier things first. Hence is the situation with lazy government workers, IMHO. However I disagree that these regulations are implemented without regard to impact to our economy and lives. For all regulations that are implemented by the EPA there is a public comment period where regulations are available in draft form and EPA considers comments. Some of the illogical, irrational comments here would absolutely be ignored by the EPA. But well thought-out, logical comments are considered. I have seen the EPA make changes based on public comments more times then I can count.

By the way, this particular law is not under the EPA but a state agency.

Since marinas are already contaminated, how will this improve things unless they are all dredged and the waste "disposed of."

Discontinuing a pollutant load will absolutely improve things. Most contaminants do have a path to natural attenuation. For copper it would be entrainment in sediment that is eventually deep enough to no longer be available for the ecosystem that is trying to be protected. But if you don't discontinue the pollutant load, then you can never reach that point.

On land as a society we have decided to designate certain land areas we are willing to severely pollute so as not to pollute the rest of the land too much. These are called landfills. Far more pollution in landfills than any of these marinas could possibly imagine. This pollution is leaching into ground water, running off into rivers and streams. Then we start trash to energy plants and start creating toxic ash, where do you think that goes?

As a society we were unaware of the consequences of landfills. But today we are and waste is not simply dumped into the ground. There are several different varieties of landfills (subtitle C, subtitle D, municipal waste, etc.). Each type is permitted to receive different types of waste based on their construction and ability to contain contamination. You can't send heavy metals and PCB contaminated waste to a municipal waste landfill. There is also significant monitoring of the landfills to ensure that, if contaminants do leach out, they don't impact drinking water. Then there are regulations about where you can put the landfill. Then you get into waste screening, recycling, waste reduction efforts, etc. It is no longer just dig a ditch and throw your trash in.

How is this new regulation not the same as the regulations that improved the landfills?

I have the cleanest most amazing storm water ditches in the whole wide world yet I drive by hundreds of miles of storm water ditches that are completely unmanaged. So where is the cost benefit and environmental benefit analysis of these regulations?

Not knowing details about where you live it is hard to answer this question. But what I can comment is that right now we are in Phase IV (I think) of the NPDES program under the CWA. In my area, this means that municipalities that are not directly on the ocean but who's stormwater is discharged to rivers that lead to the ocean are required to make improvements by a specific date. Previous stages included industrial discharges, municipal waste water plants that discharged directly to the ocean with little treatment, municipal waste water plants that discharged to rivers with little treatment, stormwater systems for municipalities on the water, etc. I think there are f5 or 6 more phases to come over the next 30-50 years before all discharges are in compliance with the CWA.

Will the clams suddenly return to the marinas, how many years will the environment in marinas be restored to original condition? How about the chemicals in pressure treated pilings, is that the next regulation?

Could be a lot of years. It all depends on local factors but eliminating the pollutant load is the first step. Pressure treated pilings already have regulations. Typically these types of regulations kick in when a major renovation is performed. Think about it like handy capped accessibility when you do a major renovation project.

A very good case can be made in this whole matter to the real problem, that being geometric population growth that is unsustainable. Yet no one will go down that path for fear of offending certain special interest groups.

Fringe environmental groups have acknowledge that population growth is a problem. What do you propose? Should we have baby quotas like in China? There is no good answer to this problem.

Are coppper paints harmful to living creatures, yes, thats why they kill barnacles and what they are designed to do. So suddenly we wake up and say "the poor barnacles?" Amazing. It will only be a matter of time until the "new" paint is also deemed unacceptable, where is the data showing the environmental impact of the new stuff? Does it still kill barnacles? Guess I'll go back to my pulled pork dinner and think about the hog effluent washing into the neuse, but hey, people have to eat.

New bottom paints are still toxic to somethings. The key is for science to limit and control that toxicity. Copper works by actively leaching. That means where ever you sail, copper is being released. The intent is to create a "dead zone" in the immediate vicinity of the boat. The new anti-fouling coatings are supposed to work by preventing growth only on the surface they are applied to and not by leaching to create a "dead zone" surrounding the boat.

The other part that you need to grasp is the unintended consequences of the use of copper based bottom paint. No one is saying "the poor barnacles". They are concerned with the other things you are killing that don't affect your boat bottom but are very important to the ecosystem. No one is advocating for letting the barnacles grow on your boat and destroy it. Just trying to find an alternative with less unintended consequences.

As to your dinner, talk to a farmer sometime about all of the regulations that are now on his industry. Many of them are far more "draconian" then this.

 

[Forrest15112]

No..... I didn't say anything about homosexuality.... I did say that cleaner air quality is good for all of us... and I credit the EPA for that... at least in California.

I know, just injecting a little humor into this debate...tough crowd.

 

[KD3PC]

Some of the illogical, irrational comments here would absolutely be ignored by the EPA.

Simply because another's thoughts are in disagreement with yours or the EPAs, does not make them illogical or irrational. It also does not make you or the EPA "right", more correct or the authority. It should not disqualify them from being a comment, as the EPA has done, even quite recently.

Your "science" or education or anything else you bring to this discussion do not make your thoughts more accurate, better, correct, etc., as they too are subject to errors, miscalculations, experience, or perspective. That before you get to politics, agendas, and the money behind them.

My perspective, whether you like it or not, allows my thoughts and logic to digress from yours. Both or neither may be valid.

But I have a right to voice them, with out recrimination and ridicule, as do you.

In your previous question to me about "people"...to me, the context and implication was clear that Faris was talking about a fair number of people, I dispute that statement/implication/thought....based on my experience and those in my peer group.

 

[kloudie1]

Quick observation again.. We keep a Steletto 27 Catamaran in a small cut which gets the rain runoff from the boatyard.. Copper and TBTF and zinc antifoulants have been removed from boats there for many (40+) years.. Yesterday, the cat had a bunch of slime and barnacles on its bottom.. Seems to me that if there were chronic problems with this stuff, we'd have a dead zone close to the yard?? Ohh.,. The barnacles have to come upstream in the mostly fresh water bayou about a half mile to get there from the brackish Lake Pontchartrain.. Doesn't seem like they'd want to go there if the runoff was such a problem.. Yes, they come upstream another two miles to the marinas on up the bayou..
Part B.. The paint works by having a coat of copper at its surface on the boat, not by having a toxic zone around the boat.. The critters that try to attach to the surface are the ones that can (but not always) get a toxic dose of copper when they physically attach.. in ablative paints, the stuff that leaves the boat is mostly the copper carrier and a small amount of the copper that was not carried off by the dead critters.. in hard paints, the copper does come to the paint surface to replace the amount that washes off or gets carried off by the dead critters..
It does not seem illogical to feel there is no problem when ya don't see a problem .. I could see/smell/taste the air pollution .. I saw the trees dying from the acid rain and other results of the air pollution.. I don't see a problem in this case.. Yes, I know that copper concentrations can be measured to be higher than someone said they should be.. but maybe because there is no apparent effect, the guidline may be artifically low??

 

[fstbttms]

If the anti fouling paint on your boat isn't enough to keep the barnacles off, what makes you think there should be a "dead zone" around the boatyard near you? Clearly a lot of you people don't have any clue about how the copper in anti fouling paint works. It doesn't kill the stuff that tries to grow on it. It isn't present in that kind of concentration. What it does is essentially make the paint "taste bad" to fouling organisms. They don't like attaching to it. But over the years, you put enough copper in the water and you've exceeded government standards for it. That's the issue. What is it with you people that unless you see dead fish floating around or three-eyed frogs crawing out of the water, you don't think there's a problem? Jeezus.

 

[JK_Boston_Catalina310]

Simply because another's thoughts are in disagreement with yours or the EPAs, does not make them illogical or irrational. It also does not make you or the EPA "right", more correct or the authority. It should not disqualify them from being a comment, as the EPA has done, even quite recently.

I have never said that someone's thoughts are illogical or irrational simply because they are counter to mine. I have said that when they are illogical or irrational. Claiming that correlations of data sets and observations is pseudoscience shows a lack of basic understanding of science and should be disregarded. If someone wanted to present a logical argument that copper is not toxic in the marine environment, that should be considered. Simply stating that copper is naturally occuring in rock and that all copper concentrations are then background (a misuse of the term) is not a logical argument.

Your "science" or education or anything else you bring to this discussion do not make your thoughts more accurate, better, correct, etc., as they too are subject to errors, miscalculations, experience, or perspective. That before you get to politics, agendas, and the money behind them.

First, why is science in quotation marks? Are you trying to imply that science is not a real thing? Or that toxicology is not real? Please explain.

Second, WTF are you talking about?! Absolutely having a background/education in geology, chemistry and biology does make your "thoughts more accurate, better, correct, etc." when discussing how a chemical contaminant (copper) is deposited and effects an ecosystem. Weather you like it or not, my degrees in geology and chemistry and 15 years of experience working in the environmental cleanup industry do make my opinions more valid then someone with no experience or education on the subject. That is why we have structural engineers design bridges and not short order cooks. This has to be one of the stupidest statements I have ever read.

Yes, scientists are human too and can make mistakes and can suffer from personal biases. But we are also trained in things like data quality control and the scientific method that were designed to reduce those mistakes.

Again, if anyone wishes to add anything to the discussion of a supported opinion that copper is not a marine contaminant, please do so. But to date, the only thing that has been added was one paper from one of the largest manufactures of copper for bottom paint.

My perspective, whether you like it or not, allows my thoughts and logic to digress from yours. Both or neither may be valid.

If you were using some kind of logic, yes. But simply stating an uniformed, unsubstantiated opinion is not logic.

But I have a right to voice them, with out recrimination and ridicule, as do you.

You have the right to voice your thoughts and opinions. But you absolutely DO NOT have the RIGHT to do that without recrimination and ridicule. Everyone else has the right to recriminate and ridicule your statements if we so wish. The defense against this is to have logical and supported thoughts and opinions that can with stand the recrimination and ridicule.

In your previous question to me about "people"...to me, the context and implication was clear that Faris was talking about a fair number of people, I dispute that statement/implication/thought....based on my experience and those in my peer group.

I challenge your experience then. Based on the number of Toyota Pyrius, Fair Trade Coffee, GMC Volts, Smart Cars, Nalgene water bottles, canvas bags, organic foods, etc. there is a "fair" number of people willing to pay a little more for items to do what they feel is "right". As far as your peer group, can you name one state in the Union where those items are not being sold in high numbers?

If you are limiting your peer group to simply your buddies at the bar (or coffee house or marina) then you may be looking at too small of a cross section.

 

[fstbttms]

I have never said that someone's thoughts are illogical or irrational simply because they are counter to mine. I have said that when they are illogical or irrational.

And there is plenty of that going on in this thread. Holy mackerel.

 

[JK_Boston_Catalina310]

If the anti fouling paint on your boat isn't enough to keep the barnacles off, what makes you think there should be a "dead zone" around the boatyard near you? Clearly a lot of you people don't have any clue about how the copper in anti fouling paint works. It doesn't kill the stuff that tries to grow on it. It isn't present in that kind of concentration. What it does is essentially make the paint "taste bad" to fouling organisms. They don't like attaching to it. But over the years, you put enough copper in the water and you've exceeded government standards for it. That's the issue. What is it with you people that unless you see dead fish floating around or three-eyed frogs crawing out of the water, you don't think there's a problem? Jeezus.

Perhaps I stated that a little too simply. I would agree with what you are saying for non-ablative paints but for but for others it is more like trying to keep fresh biocide just around the boat.

Here is a simple explanation from Bluewater:

How Antifouling Paints Works

ADDRESSING FOULING
The best answer to this problem is antifouling bottom paint. These paints reduce or eliminate any marine growth that develops on your boat's underwater surfaces. Antifouling paints do this by using biocides (chemicals) that slowly release during the season to repel underwater aquatic life. Most of the antifouling paints use cuprous oxide (copper) combined with other mysterious "stuff" to get the job done. Here are some basics:
CONTROLLED SOLUBILITY COPOLYMERS
These antifoulings are partially soluble. That means that as water passes across the surface of the coating, it wears down very similiar to the way a bar of soap would wear away. The physical action (friction) of the water over the surface steadily reduces the thickness of the paint at a controlled rate, which results in always having fresh biocide at the surface of the paint throughout the season. The paints should be used in high fouling areas. Boats painted with the Copper Pro and Copper Shield series paints can be hauled and relaunched without repainting since the biocides are chemically bound to the paint film and are only active when in the water. The longevity of these coatings is related to the thickness of the paint.
Products Copper Pro SCX 67 Copper Pro 67 Copper Shield SCX 45 Copper Shield 45
ABLATIVE ANTIFOULINGS
Ablative antifoulings wear away with use like the controlled depletion polymers but at a much less controlled rate. Ablative antifoulings are affected more by water temperature, salinity and alkalinity than are the controlled depletion polymers and generally wear away faster. They are less expensive than controlled depletion polymers and they provide excellent antifouling protection but they don’t last as long as the Controlled Depletion Polymers Or Controlled Solubility Copolymers.
Product Copper Shield 45 UNO
HARD ANTIFOULINGS
The technical term for these types of antifouling paints is ‘contact leaching’. The paint dries to a porous film that is packed with biocides, which leach out on contact with water to prevent fouling growth. This leaching is chemically designed to release biocide throughout the season, but the amount will steadily decrease until there is not enough biocide coming out of the paint film to maintain fouling protection. Once the biocide is exhausted, the hard paint film remains on the boat. Hard antifoulings do not retain their antifouling ability out of the water and cannot be hauled and relaunched without repainting. One of the main benefits of this type of antifouling is its resistance to abrasion and rubbing. This makes it ideal for fast powerboats, racing sailboats or boats where the owners have the bottoms scrubbed regularly. Most hard antifouling paints can be wet sanded and burnished prior to launch to reduce drag and improve hull speed.
Products Copper Pro SCX 67 HARD Copper Shield SCX 45 HARD

Sorry for any confusion from my earlier post.