9 Problems With Boats In Saltwater (And What You Can Do)

Not all water is created equal.

Freshwater and saltwater, in particular, have different properties, and saltwater isn’t always boat friendly.

Here’s what you need to know about problems with boats in saltwater:

What Are the Effects of Saltwater on a Boat?

Most yachts and boats are used in freshwater and have a construction that is designed for inshore use.

This means that they’re not built for the salty ocean waters. This doesn’t mean that your boat will stop working if you drop it in saltwater, of course.

However, corrosion (like boat cancer) occurs quickly and can be quite devastating.

Freshwater doesn’t pose many boats, but saltwater can corrode metal up to 10 times faster.

Not only that, boating on the ocean can be rough on your hull, especially if it is designed for inshore boating.

9 Most Common Problems With Boats In Saltwater

The main way to keep your boat happy in saltwater is to be vigilant.

You can avoid most problems by protecting your boat beforehand.

Here are nine of the most common problems and what you can do to avoid them:

1) Issues With Anodes:

When you’re boating in freshwater, your boat should be using magnesium anodes.

When you change to saltwater boating, you’ll either need to swap your magnesium anodes for zinc or aluminum.

They should be replaced annually anyway, so make sure you get the right ones, depending on where you want to go.  In saltwater, you should go for aluminum anodes that will provide more protection than zinc.

If you are keeping your boat on a trailer, they might last up to four years, but generally, you need to change the anodes yearly to be on the safe side.

It’s effortless to change them for new ones. You locate them on the outboard motor and use the appropriate wrench to remove and replace them.

2) Outboard Motor Problems:

The easy way to take care of your outboards and avoid corrosion is to flush the outboard with freshwater as soon as you return to the dock.

Most outboards come with hose attachments, which makes the process easier.

On our outboard motor, we always do this as soon as we detach the motor. We bring it home with us and leave the boat at the marina.

This way, we make sure nobody steals the engine, and we have a good routine to get the saltwater off the moving parts.

3) Sterndrive or I/O:

Sterndrive engines are a little more of a hassle when it comes to transitioning to saltwater boating.

Some come with hose attachments, but for the most part, you’re going to have to pay special attention to all of the crevices where saltwater may sit.

Flush them in freshwater as well as you can, especially the risers, water pumps, and manifolds.

While saltwater engines come with cooling systems that will flush the saltwater out, a manual flush or wash (with freshwater when you get back to the dock) is a good habit to develop.

4) Problems With the Bottom Paint:

Antifouling paint is imperative when it comes to saltwater unless you have a boat lift.

Depending on what type of boating you are doing and how/where you are putting your boat in the water, the best solution to bottom paint might change.

Because of that, I suggest doing some research, possibly even going to a bottom paint manufacturer to ask for their advice.

There are many types and qualities of anti-fouling bottom paint.  People in the business will know exactly which type of paint is perfect for your boat, and remember to let them know that you are heading for saltwater.

Remember that salt is abrasive and harsh. You won’t be getting the shine you had on your fiberglass and wood, as you did when you only boated in freshwater.

The salt in the water will tear more on the paint and cause the boat to depreciate a little faster.

5) Electrical and Hardware Issues:

Make sure that you get marine-grade quality hardware and electrical connections.

When you’re inland, you can get away with using automotive-grade equipment, but in the harsh saltwater, your equipment won’t last.

Try to keep the bilge as dry as possible.

The electrical connections to the bilge pump will corrode quickly if not taken care of. You might even need to reseal them.

6) Barnacles:

Barnacles may become an issue if you are storing your boat in a saltwater harbor.

To prevent algae and barnacle buildup (which can damage your hull and slow down your boat in the water), take advantage of a hull cleaning service that may be available.

Otherwise, you can get in the water yourself.

7) Avoid East with Lubrication:

Lubrication isn’t just a good thing to have to make sure things are moving correctly.

They also help protect against rust.

Some marine grease can be applied to your outboard steering, tilt, tube, engine trim mechanism, as well as the engine couple, and gimbal bearing (if you have a sterndrive boat).

Look for any moving parts made of metal: hinges, links, rollers, latches, etc.

If it is moving and metal, put some lube on it for protection and smooth performance.

8) Problems with the Trailer:

Saltwater will do a number on your boat trailer if you’re not careful. Aluminum trailers are heartier with saltwater.

Ensure you pay attention to the electrical components (lights, brakes, etc.) coming into contact with the water. Also, watch under fenders to make sure there isn’t any sitting water.

Drum brakes easily hold water, so wash out any water pooling in those crevices. There are great drum brake flush kits to help extend the life of your brakes. If you can, swap to a disk brake system. They are easier to maintain and are more accessible.

Some silicone grease will help protect the connectors from issues like corrosion. Just like your boat, make sure you also rinse off the trailer when you’ve pulled your boat out of the water. Check that the brake lights work before you leave the dock.

9) Vegetation Issues to be Aware of:

The last problem you might run into (which is easily avoidable) is to check for vegetation.

Saltwater harbors and oceans are home to many different types of algae and vegetation, which can be dangerous in freshwater lakes and streams.

Some are invasive species. Others bring bacteria, which could upset the freshwater ecosystem.

Educate yourself on the vegetation in the area you are heading for. The easiest way to do this is to contact a local marina and ask the local boaters.

They will know what to look for, and if there are any specific issues, you need to consider them.

Can All Boats Go In Saltwater?

Not all boats are built for saltwater.

While freshwater boats will float on saltwater, their flat hull design makes them susceptible to waves and the highly saline water degrades the hull and propulsion system.

It might be hard on the materials, and there are some issues to be aware of.

You can read more in our article here in our article about how each boat type reacts to saltwater.

How About Depreciation On Saltwater Boats?

Whether you buy a new boat or an older boat, you’ll likely have to deal with depreciation.

But how much will your boat depreciate over time?

You’ll lose money to depreciation, insurance, maintenance, repairs, dock fees, and even storage. 

You’ll spend time taking safety courses, washing your boat, making repairs, calling insurance companies, bringing your boat to and from boat ramps or docks, and you’ll probably have to do all of this while you’re on vacation.

We have written an extensive article about depreciation on boats.

This article will give you a starting point if you are looking to buy a saltwater boat.

Can Aluminum Boats Go in Saltwater?

Unfortunately, aluminum can dissolve away if put in saltwater unless you maintain it and protect it from corrosion.

This happens via galvanic action: when one metal is more conductive, it connects to a less conductive metal, and they are both in water, especially saltwater). 

The more conductive material (the aluminum boat) begins to fall apart or corrode.

You can reduce this by painting the vessel with a coating that provides electrical resistance and acts as a barrier in the water between the salt and aluminum.

Here are five more tips to help prevent this type of corrosion in aluminum:

1. Try not to mix metals.
2. Ensure your anodes are all securely fastened, so there is definitely firm contact with the metal (to protect it).
   • (This is easy to do, and you need to turn the wrench another inch if they are loose.)
3. Repair scratches and paint chips as soon as possible.
   • This will ensure that the saltwater does not reach into the wood or the aluminum below the painted parts.
4. Don’t use an automotive battery charger when you’re on the boat.
5. Keep all of your metal debris out of the bilge.