Can You Use A Trolling Motor In Saltwater

Electric trolling motors help anglers catch more fish.  Whether you are using it to reposition your boat for the perfect cast or you are tracking down finicky trout with trolling spoons, the electric trolling motor has made its mark on freshwater fishing.

Those same benefits have also caught the eye of avid saltwater anglers.  I personally enjoy fishing saltwater estuaries in the Pacific Northwest and an electric trolling motor could make fishing much easier.  However, I’ve heard that using a freshwater trolling motor in saltwater is a great way to kill the motor.  But is that true?  

I decided to do some research and asked some fishing buddies to way in on the subject. 

So, can you use a freshwater trolling motor in saltwater?  Yes.  A freshwater trolling motor can be used without immediate damage in saltwater.  However, there is increased risk for corrosion on metal components.  Apply a thin coat of oil or grease to exposed metal and rinse the trolling motor with freshwater after using it in saltwater.  Keep in mind that most manufacturer warranties will not cover damage from saltwater use.

Now, let’s go over what I’ve discovered and why you may want to invest in an electric trolling motor for your next saltwater outing.

A note on manufacturer warranties

Before you consider using a freshwater trolling motor in a saltwater environment, always review the manufacturer’s warranty.  Companies like MinnKota and MotorGuide void the warranties on freshwater trolling motors used in saltwater.  

If the warranty is important to you, don’t use it in saltwater.  Always consult the user manual and contact the manufacturer if you have concerns about using it in saltwater.  

More than likely, your motor will be fine in saltwater if the proper precautions are taken to protect it.  Ultimately, you should use your own judgement based on the model of trolling motor you have and how often you plan to use it in saltwater.

Protecting your trolling motor from corrosion

Freshwater trolling motors are not made with corrosion resistance in mind.  It’s just too expensive to added stainless steel components and additional rust proof coatings if it’s not needed.  Freshwater does not cause metal to rust easily, assuming the motor has a chance to dry between each use.  

Saltwater, on the other hand, is a different story.  Even short exposers can cause severe corrosion on unprotected metal components.  

That’s why following a few simple steps before you get on the water can add years of life to your trolling motor.

Coat exposed metal with grease or oil to reduce water contact.  Corrosion preventatives like WD-40, Corrosion Block spray or marine grade grease are suitable for most applications.  

I find Corrosion Block spray to be the best all around rust preventative for all metal parts and electrical connections on a trolling motor.  One 12 oz can last for many trips and is fairly inexpensive on Amazon.  It’s also ideal for other marine applications.  Keep some on hand and you won’t be sorry.

Generously coat the mounting brackets, prop nut and pin, shaft, metal fasteners and any electrical connections with your choice of oil.  I use a dab of marine grade grease on transom lock down bolts when I feel extra protection is needed.

Utilizing corrosion resistant products goes a long ways in protecting freshwater motors against the ravages of saltwater.  With that in mind, never moor a boat with the trolling motor left in saltwater for extended periods of time.  Eventually, irreparable damage will occur.

The importance of rinsing with freshwater

If there is only one thing you do to extend the life of your trolling motor, simply rinse it with freshwater after using it in saltwater.  

All it takes is a quick rinse at home with a bucket or garden hose.  Start on the shaft and work your way down to the lower unit and prop.  Be careful to avoid spraying the control head.  Forcefully spraying the control head may expose sensitive electronics to water.  Instead, use a damp rag to wipe down all other surfaces.

Saltwater corrosion starts immediately after contact with unprotected metal.  The best way to stop rust before it starts is to rinse with freshwater as soon as you pull your boat out of the water. 

Keep a jug or plastic bottle filled with freshwater in your vehicle.  Once the boat is back on the trailer, give the trolling motor a quick splash using the bottled water.  You can then do a more thorough cleaning at home.  

Spending the extra time to apply corrosion blocking spray and rinsing the motor with freshwater will go a long ways in providing years of trouble free use.

Damage to electronic components

One of the misconceptions I hear a lot is that saltwater will damage the electronics in freshwater trolling motors.  It’s generally thought that saltwater shorts out power connections.  

The truth is, the lower unit on trolling motors are sealed to prevent leaks in both salt and freshwater.  Electrical connections exposed to water will short out when power is applied whether it’s fresh or saltwater.  The problem is a leaky seal, not the type of water.

Now, I will admit that saltwater is harder on rubber seals than freshwater so premature leakage may occur if you don’t first protect the motor as described earlier.

You also should avoid excessive salt spray and splashing on the control head of a freshwater trolling motor.  Many freshwater motors don’t add water tight seals to the control head so electrical damage can occur.  This is a precaution you should take whether you fish in fresh or saltwater.

Real world testing

I know several anglers who use their freshwater trolling motors for occasional saltwater use.  Usually 3 to 4 times a season.  Not one of them has had any problems over the years.  The motors function normally and with added care, corrosion is kept to a minimum.  

Only one person had rust problems with their transom mount bolts but they admitted it was a lack of maintenance and grease application.  

Another angler warned that high end trolling motors with automatic stowing or lift-assist can drag saltwater up into sensitive areas of the motor as it lifts out of the water.  For those types of trolling motors it is not recommend to use freshwater models in saltwater.

I’ve used an inexpensive MinnKota Endura, purchased 15 years ago, in saltwater several times a year.  It still functions flawlessly to this day.  I firmly believe it’s lasted so long because I took steps to protect it from corrosion by applying protective oil and rinsing with freshwater.

What about constant saltwater use?  It’s a fair bet that you can keep a freshwater trolling motor functioning in saltwater even with constant use.  But, if that is your plan, just consider upgrading to a saltwater trolling motor and spare yourself the headache.

Trolling motors designed for saltwater

The most popular makers of trolling motors like MinnKota, MotorGuide and Watersnake have recognized the popularity of trolling motors for saltwater use.  Therefore, each manufacturer offers a saltwater line of motors for anglers looking to use their boats in protected bays, brackish sloughs and other coastal environments.

Here’s what makes saltwater trolling motors more durable and safer to use in these harsh conditions.

  • Corrosion resistant internal and external components
  • Fully encapsulated electronics (lower unit, auto pilot components and control head) 
  • Special corrosion resistant coatings

All of these features come at a premium price but it may be worth it for long term durability.  Standard maintenance is still required to keep the motor in working order.  Manufacturers still recommend rinsing all trolling motors with freshwater after use.

Final thoughts

Using a freshwater trolling motor in saltwater is not the end of the world.  With general care and some added precautions you can use your freshwater trolling motor without much trouble.  

For those of you who need more robust trolling motors for harsh conditions, check out the MinnKota Riptide motors and MotorGuide Saltwater series to get the best saltwater protection.