Fresh water boat use in salt water.

I asked about this on a local fishing forum but would like some of your opinions.

My nephew is rushing to buy a boat without doing too much research. I know nothing about boats so I'm asking here.

He found a 17 foot boat, the manufacturer is Cobray or something like that. It is an inboard/outboard made for fresh water use. He called the company that made the boat and the woman stated he would ruin the boat if he used it in salt water.

I think he is making a mistake and should find another boat. Am I wrong? Let me hear your opinions.

IWhat type of motor ? If you do a good flush of the motor after salt water use all should be fine. I have run many I/O in salt water and I flush it after every use and have never had a issue.

Gotta flush them after running in the salt.

I prefer outboards for saltwater and that is what I run.


I/0 are nice, but a real pain to maintain for freshwater, let alone salt.

I would want an Outboard but that's me....

I'm far from an expert but have been around boats all my life. My family has had boats on Lake Erie for as long as I can remember and I've owned my own boats for the last ten years. I lived up in NC for a few years and have made Gulf Stream runs out of Wilmington (40+ miles offshore) in everything from a 22ft center console to really nice Bertram sport fishermen. Here in FL I live on a canal that leads directly in to the Atlantic and spend most weekends on the water.

Where is he going to use it? I see you are in NY, is he? There's not many places in NY with saltwater I'd use a 17ft boat. Ya'll tend to have rougher weather up there. You would really have to keep an eye on weather and sea conditions and pick your days. Especially since he sounds like a newbie to boating.

How much is he looking to spend? It's a buyer's market right now for used boats. No reason to rush in to buying anything if you have the cash on hand. You may be surprised what your money will fetch in the market.

I've never heard of a Cobray boat manufacturer. But I'm not the be all end all of boats. There are a lot of small manufacturers (or at least there were, the economy has hit them hard) up and down the east coast. Many of them built fine boats.

If the boat manufacturer said saltwater will ruin it I would listen. The fiberglass won't know the difference between fresh and salt but the metal hardware will. Builders that build for salt water use, use metal hardware that can take the salt. Brass, stainless steel, Bronze, etc. Plus they take in to account galvanic corrosion. Fresh water builders generally don't do these things. It helps keep costs down. At best replacing the hardware can be expensive and dificult. At worst a thru hull fitting will corrode and sink the boat or your motor mount will let go.

The motor and running gear, if it has been well maintained up til now and he will continue to maintain it, there is no reason to worry. As long as he is trailering and flushing the internals and washing the externals after every use he should be good.

A better place for advice would be a local marina. You might also try The Hull Truth It used to be a good site. It has declined recently but there are still some good folks there.

For what it is worth, I would listen to the manufacturer. I have a 22' Trophy Pro I/O and dry dock . I flush the system for the minimum of 20 minutes each time I return home. It only takes me 10 minutes from ramp to home from the IC here in NC. I also have a contraption that I hook up to my muffs via the water hose. It's made like them fertilizer contraptions for when you water your lawn. I put White Distilled Vinegar in it. It holds about a gallon. As the water hose pushes water to the muffs to flush the motor, it siphons the vinegar which helps dissolve the salts. Old Timer showed that to me many years ago and it has helped the life on the units and maintenance.

Gene @ HSGI

Boats made for freshwater use different metal components than for saltwater. If you use the boat in salt water the anodes that keep critical parts for corroding due to galvanic corrosion would not be effective and possibly make critical (expensive) parts corrode at an accelerated rate destroying your investment. If the company advises against it you can bet the corrosion would destroy the boat in very little time. goodluck and remember to have a compression check done on the motor before you buy, even if the motor is running.

Somewhat true. The anodes are different for salt water as opposed to fresh water. Salt water requires pure zinc for anodes whereas fresh water can use less expensive magnesium anodes. I bet you are thinking of Cobalt boats. Using it in salt water for a weekend (with proper anodes) won't hurt it as long as you flush it good afterwards. I wouldn't want an I/O for continuous salt water usage.

I have a 17; aluminum Tracker with Mercury outboard. I’ve used it a couple of times a year for the past 4 years in salt water. Every time I pull it out of the salt water I wash off the boat and motor then slap the ear muff style “things” on the motor to flush the cooling system. I’ve never had any problems.

Sorry for the late post, I hunt in the winter and only look at the fishing section when it starts to warm up.

I would go with the manufacturers recommendation. If you don't just make sure your expectations are appropriate. I have owned several boats for saltwater use and 2 Nitro bass boats. My one Nitro I used regularly as a flats boat and for close to shore Cobia fishing. It worked great, was well maintained and it did eventually rot from the inside out due to saltwater erosion. I had my 1st one, fresh water only for 12 years and sold it in used but good condition. The 100 HP Mercury was in very good condition. My 2nd Nitro I used in saltwater about 80 percent of the time lasted me 10 years and was ruined when a neighbor bought the 150 HP Mercury from me for $1500. The motor was in good condition it was the boat that was ate up. We wash the boats religiously after every outing. It is literally a ritual. If your going to use it for saltwater it will work but expect decreased life expectancy.
On that note Nitro makes an excellent boat and some have told me I get a lot of service life from my boats. Not only do I use them but my brother and I pretty much rotate our toys. He is big into quads and UTV's Me boats and ATV's so between us our equipment is used and abused regularly. We take good care of it but it is heavily utilized.

I've grown up around boats, worked at multiple boatyards and marinas and have gotten asked this many times and I'll give you the same answer I give everyone:

short version: FLUSH THE ENGINE AFTER EVERY USE!!!!

not so short version: some manufacturers will say certain things shouldn't be used in salt water for various reasons (in my experience they generally say this about older products, don't ask me why they just do) but in my experience as long as the engine is flushed out properly after each use then the I/O system should be fine. 2 things to keep in mind.

1. flush the engine as soon as you get the boat out of the water, unless you have to don't wait until you get home to flush the engine out. I say this because even the drive home is enough time for the saltwater to drain out of the system and salt crystals to form.

2. don't skimp on the time you spend flushing the engine, yes gas is expensive but the gas you will burn letting the engine flush for 5 or so minutes will cost way less than a repair when something rusts out.

also worth bringing up it give the the whole exterior of the outdrive assembly a good washdown as well when the boat comes out of the water.

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