Antifoul performance can be affected by a lot of factors. And any one type of antifoul can be affected in subtle ways by these same groups of factors.
The reality is that as human habitation encroaches along natural coastlines the foreshore is being physically modified and polluted. And the natural habitats of indigenous species are impacted by these changes including the introduction of non-indigenous species brought in by ocean currents, international shipping, and recreational vessels.
To understand how antifoul performs differently over the variety of different ecological environments, we need to understand how the biodiversity is existing in each environment.
Having natural coastlines modified to include wharves, docks, marinas, and sea walls including land reclamation and the introduction of building materials reduces the natural environment for many species. Industry, Urban sprawl city development and areas with direct marine activity are usually associated with substantial pollution from wastewater. Agricultural runoff produces excessive inorganic nutrients, nitrogen, phosphorus into these streams and rivers.
These nutrients end up feeding the short-lived algae blooms from Wence the after effect of decomposition of these microorganisms consume all the oxygen suspended within the water column, this lack of oxygen subsequently suffocates the local communities creating dead zones devasting estuaries and waterways leading to the ocean prolificating the existence of only the ultra-hardy.
Marinas with human waste, oil, and fuel leaks, antifoul leeching into the water column Create their own localized dead zones Especially those where constant dredging stirs up years of built-up contamination of heavy metals which have leeched from antifoul coatings which are then washed down the channels into the habours creating more than an effect on the local ecosystems.
This mix of contaminants, metals, tannins, nutrients, algae blooms, create a sticky blend that adheres to everything. Hulls and decks above the antifoul line, presenting as a yellow stain. Once this adhesive layer takes hold looking like slime it starts to filter and collect more particles from the water column developing into a mixture of living microorganisms silt mud and algae that feed newer larger pupae.
The fact is even as we try to co-exist with our natural environments, we cannot help but add contamination to an already fragile ecosystem.
To control how nature is responding to us encroaching on them, we double down by adding further biocides, pesticides, and other contaminants into the waters just to keep our boat hulls clean.
This is where we look at the environment, the eco system we are putting our boats in. What can we expect from this area?
Are we floating above Mud in a marina? How contaminated is that mud from antifoul leeching? What is the mud made up of? What biodiversity can that mud support? What else is nearby that can maintain a healthier eco system? Mangroves, estuaries, habours, water flows? or vertical concrete walls, wooden piles, rock walls? is it in a tidal river? Is there industry along the river? Is it a tidal estuary, an inland tidal habour? It could be a marina at the end of an inland habour, or a marina centered amongst central city. A marina in open water, or a marina that is affected by an open ocean flow that sends warm water from the tropics carrying all manner of biodiversity like an ocean highway.
To choose an Antifoul type that will cover all these factors can feel a little like a lottery. As the owner operator of Auckland Marine Boat Valet It has been my experience that soft antifoul self polishes and sheds itself losing settlement foul or other foul that attaches in a more mechanical way like weed algae, barnacles, muscles, or oysters. Soft antifoul will let it go. What we call a foul release. If you rub on the surface of the softer ablative antifoul it will release a cloud of paint revealing a fresher surface below. It should be expected that less will remain on the boat at the end of the season. After a while, this buildup can become unstable requiring complete removal and starting again. This process is necessary for all types of antifouls.
Semi soft is my preference as it will give you a longer duration and still offer up that self-polishing aspect.
Harder Antifouls are designed for bigger boats that are regularly blasting the hull surface by the sheer bulk of the vessel moving through the water. Harder antifouls are also used for planning hulls where the power of the waterflow cleans the hull. Racing yachts also use the harder antifouls as they can be manually cleaned and polished by hand using sandpaper or scotch bright scrubbing pads on a more regular basis before racing.
Anybody who has sanded antifoul will understand just how much effort is required to wear down Medium to Hard antifouls. It should be noted at this point that harder antifouls that are not used very often will become ladened with growth. They rely on the chemicals suspended within the body of the antifoul to protect the hull in a static environment. They are reliant on the effect of the water blasting to remove foul. But in a static situation their performance aspect is not utilized.
Barnacles which start off as a tiny pupa drifting through the water column often prolificated from mangroves searching for a habitable space where they can make their home and filter the water for plankton and other nutrients. They grab hold with their antennae which has a glue-like substance. The Barnacle secretes the calcium hard plates that completely encases them. These cones are made up of six nearly fitted plates that form a circle around the crustacean. Four more plates form the door which the barnacle can open and close depending on whether it is in a tidal situation to maintain moisture for survival. When open the Barnacle extends all six pairs of these feathery like feeding appendages called cirri, are jointed, and set with feathery hairs which brush through the water collecting plankton for the barnacles to eat. The legs also have gills for the exchange of gases. Barnacles excrete a cement like glue through their antennae onto the surface, they cement themselves onto the surface and grow as they feed. Barnacles prolificate with other Barnacles who are nearby, they extend out a tube offer a couple of inches long filled with sperm that they fertilize a nearby barnacle. Therefore, we see many clustered together on the boat hulls. This grouping will often restrict the vessels’ ability to get up on the plan, will reduce fuel efficiency and handling. Harder antifouls with limited ablative effect are unable to unlock the potent potential held withing the body of the antifoul. Boats moored in fresh water will often benefit more from harder antifouls as the salt water is what activates the ablative efficiency.
We are lucky to be living in an era where we are learning of different methods and products to give us the solution. We are now being offered Antifoul wraps antifouls with high silicone content, antifouls that are predominantly copper, antifouls that are technologically advanced. In the right conditions all of these will work as prescribed. But which one offers an all-round solution? Cost effectiveness and Durability. My personal preference is Altex no 5 and its slightly harder cousin the sea barrier 3000. I find that it self polishes nicely, it has a strong copper content and an effective acceptable level of biocides and foul retardants that stops the spread of unwanted biodiversity.
Changing antifoul types requires a primer medium to guarantee adhesion of renewed antifoul. If we know then we use like for like if we want to change then we will again use a primer medium to change to a new antifoul. While we have a preference, we remain respectful and open to friendly discussions a sharing of experiences with our boating community.
The Antifoul services we offer are competitive and knowledgeable. We will provide the right solution for boat antifouling and polishing to maintain efficient performance of your boat through the water. We offer good advice, save you money and time. Boat Antifouling and Antifoul services are offered in all the main marine centers throughout Auckland. So, when you are thinking of Auckland antifoul give us a call.