Can I Leave My Boat in Saltwater?

Storing your boat is a very important decision that can determine its lifespan. If you store your boat on the water—especially saltwater—it is extremely important to properly winterize and remove as much salt out of the systems as possible before leaving it. How long you can leave it on the water is determined by a number of factors.

The amount of time you can leave your boat on saltwater depends on the boat’s hull material, the type of paint, the water conditions, and how often you use it.  As a general rule of thumb, never leave your boat out in saltwater for longer than 7 days unless it is specifically made for saltwater.

There are, of course, many people who cannot take their boats out of saltwater when storing it. Luckily, there are a series of steps you can take to prevent salt corrosion. First, it is important to know which factors are responsible for different types of salt corrosion.

What Factors Contribute to Salt Corrosion on a boat?

The factors that affect how long you should leave your boat on saltwater make it difficult to pinpoint exactly how long you have before damage can occur.

The type of construction materials is the main determining factor for how long to leave the boat in saltwater. Saltwater boats are usually built out of steel, aluminum, or fiberglass, which makes them more durable against salt corrosion.

Freshwater boats may have different hardware installed, but they too can sit in saltwater for 7 days as long as the boat and its engine are sufficiently rinsed off afterward. You have to use anti-fouling paint on your freshwater boat if you are going to take it in saltwater for longer than that.

Water conditions also have an effect on how fast your boat will corrode sitting on saltwater. Sometimes the water will have high salinity levels, warmer temperatures, or ice that can affect its durability. Mussels, barnacles, and algae flourish in warmer salt waters, which increases the weight of your boat. This in turn requires your engine to work harder and causes it to wear down faster.

Salt can eat away at paint over time if it isn’t properly maintained (rinsed and dried) after each use.  To combat this, it is important to use anti-fouling paint on your boat because regular paint will crack and peel much easier. Experts suggest using copper-based cuprous-oxide biocide paint to keep algae and other sea life from attaching to your boat.

Boat Engine Deterioration In Salt Water

Prolonged exposure to saltwater is capable of corroding your boat engine, which is called galvanic corrosion. In fact, saltwater corrodes the metal on a boat ten times faster than freshwater. The salt will also absorb moisture from the air and speed up the process.

Other parts of your engine that are negatively affected by salt are the manifolds, block, exhaust, driver, and rise system.

Luckily, most boats made for saltwater come with closed-loop cooling or cooling systems that flush out the engine with freshwater to keep it from being corroded. However, if you have a freshwater boat and you don’t regularly flush out the saltwater from the engine, the salt will build up in the cooling pathways and lead to overheating.

Fading Hull

The hull of boat will get scratched and fade much faster when in saltwater than in freshwater. You’ll notice the tiny scratches by the dullness of the paint.

Prolong the life of your saltwater boat’s hull by rinsing it off with freshwater after every use.

How Do I Prevent Rust When Storing My Boat?

It is extremely important to completely wash your boat and rinse it to remove as much salt as possible. This is the first step to getting your boat ready for storage after removing it from saltwater.

Invest in a salt remover product like Salt Off to fully remove all traces of salt from your boat. There are a variety of different products you can use, mostly dependent on the type of material you are trying to protect.

Check the hull for barnacles, algae, or other living matter and remove it. You may have to use a scraper. Repair any other damage to the haul and touch up paint if needed.

Thoroughly flush the engine with freshwater, taking special care to wash and lubricate metal pieces to prevent rust.

Check the sacrificial nodes on the boat for corrosion and replace them when they have shrunk to half their original size.

What if I Have to Store My Boat in the Salt Water?

If you have to store your boat on the water, the #1 thing to remember is to rent a covered marina slip so that your boat is protected from the elements.

As soon as you dock the boat, tilt up the outboard (if that’s the type of engine you have). Sitting in saltwater will speed up its corrosion and make it a home for barnacles to grow.

Next, make sure the engine and cooling system have been flushed out with freshwater. This clears out any salt that would have otherwise been sitting on the metal and rusting it over time. Most docks will have freshwater to do this.

Use a fuel system treatment to prevent corrosion and buildup of “gunk” in the tank. Many suggest using a fuel stabilizer if you are going to be leaving your boat off for longer than three weeks. Boats that are used regularly do not need a stabilizer.

In order to keep the bilge-pumps working, connect your boat to shore power or to a solar charger. Close your thru-hulls (except the bilge-pump outflow) and plug exhaust ports.

Perform a deep clean of the boat’s interior, making sure everything is completely dry. This is important to keep mildew and deterioration by salt away.

Lastly, you should fit a boat cover tightly over the top of the boat to keep saltwater from spraying into the interior, causing further salt damage.


As stated before, try not to leave your boat in saltwater for longer than 7 days. If you have to, follow the steps above to deter any salt corrosion from forming on your boat and its parts.

The most important thing to do is clean off as much salt as you can from all parts of the boat after each use. Using salt preventatives is another great way to keep the damaging effects of salt at bay.

Ward off rust or corrosion by cleaning your boat regularly, performing proper maintenance, and winterizing correctly. This will prolong the life of your boat by many years.