The Effect of Sea Water on an Aquatic Vechicle

Barnacle growth slows down boats.

Although aquatic vehicles are designed for the water travel, sea water negatively affects them in several different ways. Corrosion occurs easily in salt water, and marine growth proves negative for performance and speed. Without proper care, sea water eats boats for breakfast.

Galvanic Corrosion

Sea water works as an effective conductor. Water with minerals such as salt, or polluted water works as a catalyst for galvanic corrosion on boats. This happens when different, touching metals begin exchanging electrons, or electrical charge. This electron exchange corrodes the metals, especially in warmer water, according to the Boat Owners Association of the United States.

Crevice Corrosion

Areas on aquatic vehicles which get wet, but cannot adequately dry, begin to show signs of crevice corrosion. Especially on stainless steel, when sea water splashes or mists onto the boat, and stays stagnant in the crevices, it deprives the metal of oxygen. Without the oxygen, the stainless steel’s protective oxide layer begins to break down and rust, states the Boat Owners Association of the United States.

Stray Current Corrosion

A very aggressive form of corrosion, called stray current corrosion, happens when an actual electrical wire or battery touches metal immersed in the sea water. The salt water allows the electrical current to flow directly to any metal on aquatic vehicles and destroy all aluminum in days.

Barnacles

Sea water affects aquatic vehicles in another significant way: marine growth and speed. The longer a boat sits in the sea water, the more barnacles and moss grow on the bottom. This growth severely affects speed and performance of the aquatic vehicle, according to the website Boat Fix. They suggest a mere 40 days in sea water causes marine growth accumulation so severe, a 35 HP engine drives 12 mph slower than the first day in the water with no marine growth.

Prevention/Solution

Washing marine vehicles with fresh water after a trip to the sea represents the most important corrosion and marine growth prevention strategy, according to the website Marine Fasteners. Boat owners should also use a galvanic isolator to protect against both stray current and galvanic corrosion. This device breaks the electrical current's flow to help send it to a metal other than your boat.

References

• Marine Fasteners: Saltwater, Fasteners, and Boats
• Boat Fix: Propellers
• Boat Owners Association of The United States: Types of Marine Corrosion