Marine environments host a wide variety of invasive aquatic species that continuously attach & grow onto stationary objects. Marine growth, also known as marine fouling, can encapsulate a vessel hull & underwater components in as little as two weeks. Marine fouling significantly reduces vessel performance, restricts vital cooling intakes, adds weight & vibration, over-loads engines, and can lead to mechanical failure.
If your vessel is experiencing performance issues, it is likely attributed to marine fouling:
- Low RPM's
- High temperature
- Restricted water flow
- Sluggish performance
Maximizing & sustaining vessel performance in the marine environment is our specialty. Our skilled divers meticulously service and diligently inspect each & every component below the waterline. Together our team will keep your vessel operating at its maximum potential.
Call us today (850) 696-2828
HULL COATINGS: A quality barrier coat & anti-fouling paint application are crucial to the structural service life of any hull. Together, the barrier coat and bottom paint act as the main barrier between the outside water and the interior substrate. Though initially more expensive, the cost-effectiveness of superior paints is apparent when you look at their multi-season performance, ability to be relaunched, and no-buildup, self-polishing nature. We recommend discussing with the boatyard about their application processes and demand multi-layer thin coats opposed to one thick layer. Inferior applications will result in paint blistering and paint flaking, causing water to permeate through the gel coat and into the hull substrate, resulting in costly time & commercial repairs. http://www.boatus.com/boattech/articles/bottom-line.asp
PAINT BLISTERING: This process is similar to hull blistering but is referring to the bubbles or blisters forming under the paint itself. Inevitably this will result in paint flaking. It is imperative to apply coatings according to manufacture specifications. We typically see paint blistering appear within the first six months of a new bottom job. Experienced divers will note paint blistering, and if counteractive measures are taken by the owner, it can result in dramatic savings. Most bottom paint applications have a 1-year warranty, and recording these problems early will always eliminate headaches down the road. https://international-yachtpaint.com/en/au/support/boat-paint-problems/blistering-bubbling
PAINT FLAKING: As we know, bottom paint and the barrier coat work together to act as the first layer between your vessel and the underwater elements. Paint flaking creates a void in this duo, and over-time could become ground zero for a hull blister to appear. As divers clean and inspect the hull, they will note the size and quantity of any paint flaking that they find.
HULL BLISTERING: Also known as osmotic blistering or hydrolysis is the term used to describe small particles of water passing through the gel coat and into the hull laminates. As soon as the water enters into the laminate, it begins to dissolve any soluble materials within the laminate. The dissolved laminate molecules are too large to exit the substrate, and as time passes, the blistering gradually increases. Please see the article below and refer to page 4 for a more detailed description of this process. https://www.westsystem.com/wp-content/uploads/Gelcoat-Blisters-Diagnosis-Repair-and-Prevention.pdf
DELAMINATION: This process is referring to a more horizontal release of the layers of fiberglass along the outer hull substrate. Overstressing and high impact on the hull can cause tiny cracks or small voids in the hull materials. Over time, through normal wear, vibrations, and effect, the fiberglass layers begin to peel or release from itself. We typically see this where repairs have been made without proper compression of the fiberglass-resin-gel coat application.
Call us at (850) 696-2828 or fill out our Contact Us form to schedule a service.
CORROSION: One of the most damaging and costly, naturally occurring events seen today. Corrosion is an all-too-common result of electrochemical reactions between materials and substances in their environment. https://www.electrochem.org/corrosion-science
GALVANIC CORROSION: Refers to corrosion damage induced when two dissimilar metals are coupled in a corrosive electrolyte (saltwater). It occurs when two (or more) dissimilar metals are brought into electrical contact underwater. When a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone. http://www.boatus.com/boattech/articles/marine-corrosion.asp
ELECTROLYSIS: More commonly called "stray current" corrosion, adds an external electrical source to the corrosion equation, rapidly accelerating the reaction. It occurs when metal with an electrical current flowing into it is immersed in water that is grounded (which would include any lake, river, or ocean). This can happen if a short develops between an external current source (almost always the 12-volt electrical system on your boat or someone else's) and some part of the electrical system that is tied into the boat's underwater metals. The stray current will exit the ship from an underwater metal fitting. https://www.boatus.com/seaworthy/magazine/2015/july/marine-corrosion-101.asp
DEALLOYING: Dealloying or selective leaching refers to the selective removal of one element from an alloy by corrosion processes. A typical example is the dezincification of un-stabilized brass, whereby a weakened, porous copper structure is produced. "Discoloration" or a "pinkish hue" in brass or bronze is a sign of dealloying. https://www.nace.org/Dealloying/
BONDING & HALOING: At the first sign of haloing (burnt paint around thru-hull fittings), the first step is to inspect all bonding system connections to ensure they are clean, tight, and corrosion-free. Next would be to have a corrosion survey conducted on the vessel to determine if proper galvanic protection is being provided. If diver’s find paint haloing, they will note specific details & take photographs of the severity. https://www.passagemaker.com/technical/-through-hull-fittings-and-canaries-in-coal-mines
PROPELLER CAVITATION: As the propeller turns it absorbs the torque developed by the engine at given revolutions, i.e., the delivered horsepower – and converts that to the thrust which, in turn, pushes the vessel through the water. According to Bernoulli’s law, the passage of a hydrofoil (propeller blade section) through the water causes a positive pressure on the face of the blade and a negative influence on its back. The negative pressure causes any gas in the water to evolve into bubbles similar to those found when opening a carbonated beverage. These bubbles collapse and can cause hammer-like impact loads on the propeller blades, resulting in the observed damage to the propeller blade surfaces. We typically see cavitation pitting at the base of the propeller flukes and even on the sides of rudders. This pitting is concentrated to one specific location; this is how we determine if its corrosion vs. cavitation. https://www.iims.org.uk/introduction-propeller-cavitation/
Call us at (850) 696-2828 or fill out our Contact Us form to schedule a service.
BONDING SYSTEMS: “In the simplest of terms, bonding systems are an interconnection of underwater metallic components, including through hulls, struts, rudder stocks, and propeller shafts. Like any other critical component, bonding systems should be inspected regularly. When installing or augmenting bonding systems, connections should be made using heat shrink terminals and conductant paste such as Thomas & Betts Kopr-Shield. Completed connections should be coated with corrosion inhibitors such as CRC Heavy Duty Corrosion Inhibitor.” https://www.proboat.com/2015/04/the-mysteries-of-bonding-systems-revealed/
CATHODIC PROTECTION: One type of cathodic protection system is the sacrificial anode. The anode is made from a metal alloy with a more "active" voltage (more negative electrochemical potential) than the metal of the structure it is protecting (the cathode). The difference in potential between the two metals means the sacrificial anode material corrodes in preference to the fabric. This effectively stops the oxidation reactions on the metal of the structure being protected. https://galvanizeit.org/corrosion/corrosion-protection/sacrificial-anodes
SACRIFICIAL ANODES: Underwater anodes come in 3 materials:
- Zinc – Designed for saltwater environments.
- Aluminum – Designed for Saltwater or Brackish water environments.
- Magnesium – Designed for freshwater environments.
Depending on where the vessel will be kept determines the specific anode materials to be chosen. Proper anode monitoring & installation will significantly extend the service life of all your underwater metals. West Marine has a great video in the attached link. https://www.westmarine.com/WestAdvisor/Preventing-Galvanic-Corrosion
ANODE MONITORING: We monitor each component and its anode(s) correctly. Each ingredient and its anode(s) are bonded together and are part of the vessel bonding system. With detailed monitoring, we track each element down to the smallest detail - minor details can result in significant savings down the road. By tracking the service history of each anode, we can predict its future replacement, stocking its replacement specifically for your vessel. Accurate anode monitoring and proper anode installation are imperative to the service life of underwater metals.
ANODE INSTALLATION: Our goal is to keep your marine anodes maintained and your underwater metals protected. Before installation, the diver will remove any surface residues left behind from the previous anode. Good bonding connections ensure proper cathodic protection. Stainless steel fasteners all always used, and all anodes are made in the USA.