How Long Can a Boat Sit in Saltwater?

Many people love boating–it can be a wonderful experience to be able to get out onto the open water and away from the world. However, there are things that you need to keep in mind as far as boat maintenance goes, particularly if you are keeping your boat in saltwater.

How Long Can a Boat Sit in Saltwater?

How long can a boat sit in saltwater? A boat can typically sit in saltwater for about a week before you can start to expect damage. However, this can vary based on the structure of the boat.

If you are a boat owner, you should be vigilant when it comes to the upkeep of your boat in saltwater. This will be the best way to ensure the least damage possible so that you will not have to waste unnecessary money on boat repairs.

How Long Can a Boat Sit in Saltwater?

If you have to leave your boat in saltwater, make sure that you don’t let it sit for too long. You definitely should not leave it for more than about a week.

You also shouldn’t leave your boat sitting in freshwater for a very long time without maintenance, but you can get away with leaving your boat in freshwater for a little longer, possibly a month.

However, this does not mean that you cannot have your boat in saltwater. Some people don’t have a choice in the matter. It just means that you will need to exercise proper boat maintenance in order to prevent unnecessary damage.

How Long Can a Boat Sit in Saltwater?

What Does Saltwater Do to a Boat?

Saltwater can have many damaging effects on your boat. For example, it can do damage to your engine over time.

Because your engine is made of metal, constant exposure to saltwater can cause corrosion and rust if you don’t maintain your boat properly. Saltwater can corrode metal at a speed about ten times as high as that of freshwater.

The hardware of your boat will also be affected. The metals in the electrical wiring of the boat are extremely susceptible to saltwater damage. This is why it’s important that you keep them as dry as possible.

Saltwater can also do damage to the hull of your boat. The fiberglass on the hull will fade faster and will show scratches much more quickly, as opposed to a boat that you leave in freshwater.

How Should One Maintain a Boat in Saltwater?

Ideally, if you are going to be keeping your boat in saltwater, you will be getting a saltwater boat.

Saltwater boats are constructed differently than freshwater boats, although they still require quite a bit of maintenance in saltwater. These vessels have hulls that are designed to weather more intense conditions in the water.

Every day you take the boat out on the water, wash down the boat and trailer as soon as you possibly can. At the very latest, you should do it within a few hours.

Make sure that you hose down every essential part, including the frame, hardware, lights, fenders, axle, brakes, wiring connectors, and springs of the trailer.

A little bit of silicone grease can be good to give your connectors a little bit extra corrosion protection. You should also make sure to check for corrosion on your boat and trailer on a regular basis so that you can replace parts as needed.

Structures on the Boat

There are many things that boat owners who have to deal with saltwater should keep in mind (Specifically, you need to make sure that all of the structures on your boat are properly maintained if they are going to be sitting in saltwater on a regular basis. In some cases, this requires replacing some parts of the boat.


An outboard doesn’t require much work when you are making the transition to saltwater.

However, you need to make sure that you flush the unit with fresh water every time you get the boat back to the docks.

The outboards of boats made these days will come with built-in garden hose attachments, in order to make that job easier for you.

You should make sure to perform this rinsing for between 5 and 10 minutes in most cases. If you have doubts about the amount of time that it should take, you can consult the manual or a mechanic who will be able to help you.


The anodes of the boat are typically made of magnesium. This will work better in freshwater. However, if you are going to be keeping your boat in saltwater, you need to switch to zinc or aluminum anodes.

You also need to make sure to check them more often, since corrosion is more of a problem in saltwater.

Replace them on an annual basis or whenever you see that they are more than half wasted.


You might need to do more work to successfully transition your stern drive engine to saltwater.

These usually do not tilt out of the water, so if your boat is sitting in the water, Be very mindful of the innards. You should also make sure that you flush and spray the drive part of the engine thoroughly.

Overall, you need to be aware that you are going to have to replace parts more often if the boat is in saltwater.

Specifically, you’re going to have to replace manifolds, water pumps, and risers. Manifolds usually last a decade or more in freshwater, but only three to four years in saltwater.

Bottom Paint

Many people do not understand how important bottom paint is. You can keep a boat in freshwater without bottom paint for a couple of weeks. However, this is not something you can do with saltwater.

Go to the manufacturers of bottom paint in order to figure out exactly what kind of paint you should use. This will depend on the specific environment, as marine growth will differ between bodies of water.


Check to make sure that your boat has marine-grade quality hardware. Automotive-grade hardware is not going to work in most saltwater bodies. You will also need to make sure to keep the bilge as dry as you can since salt in the bilge is very corrosive for electrical connections and metal.

In particular, make sure that the hardware that connects to the aluminum frames should be composed of stainless steel. If it’s galvanized, you will experience very fast corrosion.

How Long Can a Boat Sit in Saltwater?

Final Thoughts

Many people underestimate the impact that saltwater can have on the structures of their boat. The truth is that you can have your boat out on saltwater, but you do need to be extra vigilant about its care in this situation.

Otherwise, you might end up having to replace parts too often or even having to replace the entire boat, which can be very costly.

If you can keep your boat in freshwater, this might be a better idea. However, some people don’t have a choice because of where they live or where they are going to be doing most of their boating.

If you have no choice but to keep your boat in saltwater, you just need to make sure that you check for corrosion on a regular basis and flush out all of the parts of your boat with fresh water after you take it out on the water.

As long as you maintain your boat properly, you should be able to keep it in the saltwater for several days without worrying about lasting damage or a host of barnacles taking residence on the bottom of the hull.

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