Buying a Used Boat: Five Overlooked Things to Check

Buying a used boat is a busy time. You’ve been scouring the ads to be able to pounce on the model you want as soon as it becomes available. There’s a lot to consider and even more things to inspect, and that’s where the trouble can start. Buyers place a lot of emphasis on a sea trial, as well they should, but there are a few checks that should be done before you do any driving. It’s easy to forget these items because of everything you’ve got going on. To keep that from happening, here are a few checks that I think are critical to getting a good used boat — or at least avoiding one with more than its share of problems.

Sea trials are important -- and fun -- but there are some fundamental checks that should come before you even turn the key. All photos: Doug Logan

Sea trials are important — and fun — but there are some fundamental checks that should come before you even turn the key. All photos: Doug Logan

Cold Start

One thing to insist upon is that the boat you’re looking at be stone cold when you get there. When you fire it up, it should be the first time it’s been started that day, and it gets more critical the older the boat is and the more hours there are on the engine. What does that do, you ask? When an engine sits for a long period, or even just overnight, the oil pressure between all the metal surfaces bleeds off. If there are excess clearances in, say, the connecting rods or main bearings, or even too much clearance between the pistons and cylinder wall, it will often present itself as a telltale metallic knocking, ticking, or slapping on cold start-up. If the boat has been started too soon before you arrive to look at it, you will have lost the opportunity to listen for noises on cold startup.

Snap a photo of the engine hours before heading out on your sea trial, and check the number again when you come back. Doug Logan photo.

Snap a photo of the engine hours before heading out on your sea trial, and check the number again when you come back.

Engine Hours

We all love boats with low hours on them, right? Of course, because it means there’s more boat left for us to use once we buy it. Here’s a trick. Check the hour meter when you first get aboard, before start-up, but also check it again after you come back from your sea trial. If the hour meter hasn’t moved, now you know why the engine has such “low hours” on it, and it might be best to move along to another prospect.

Engine Oil

Having a look at the dipstick seems like a basic inspection, but you’d be surprised how often it gets overlooked. Pull the dipstick and study the oil. It shouldn’t be inky black (unless you’re looking at a diesel engine) and if it has just been changed, it should still look close to the way it does when you pour it from the bottle into the engine. There should be no evidence of water in the oil. If there is, you might be looking at head gasket problems. Also smell the oil. It should smell like oil, not like gas. If there’s a strong gas smell, it might indicate problems. Also, while you’re at it, unscrew the oil cap and look underneath it. It should have dark brown residue on it, but anything milky or resembling chocolate milk might also indicate problems with head gaskets.

Drive Oil

On MerCruiser products, whether it’s an Alpha or Bravo drive, the engine compartment has a remote drive oil reservoir. Because the reservoir is translucent plastic, it’s easy to see if the oil is up to the full line, but you’ll want to pull the cap off and check inside for signs of moisture. Water in the drive oil will tell you there’s a leak somewhere in the drive that’s allowing water to seep into the gear case. If this has been going on for a long time, the gears in the drive might be subject to corrosion and pitting, which generates excess heat while in use. It’s quick and easy to check, and there’s usually nothing wrong in a maintained boat — but you don’t want to overlook it.

Check all the main elements of the trailer  you're buying with the boat. This one is sporting a new coupling assembly. Doug Logan photo.

Check all the main elements of the trailer you’re buying with the boat. This one is sporting a new coupling assembly.

Trailer Health

Most of us are buying boats we can tow behind our trucks to get to the water. That means your purchase is twofold, and the trailer is an important part of it. Before you back the boat into the water, take a moment to do a walkaround inspection of the trailer. You don’t need to break out a magnifying glass, but you do need to have a look at the important parts. Check the condition of the bunk carpeting or the bunk rollers if so equipped. Look at the backs of the wheels to see if there are any indications of brake fluid or bearing grease leaking. Look at the center of the hubs, too. I also like to check the condition where the leaf springs attach to the bogeys — if dual axle — and to the frame. A little rust is to be expected. A lot of rust can leave you stranded when the spring mount fails. Checking the lights is always a plus, as is checking the condition and working order of the coupler, surge brakes, and tongue jack.

A previous version of this article appeared on Boat Trader in May 2015.



  1. Hi, I pickup a 2007 4 Winn, Volvo, 5.7 liter, V8. It need work to say the least. It has set about 2 years. The Gimbal Bearing is bad. What should the cost to replace it. The body need gelcoat. Let me know any thing do or look for. Thank you

    • Chris says:

      The price differs depending on where you look and whether it’s for an alpha or bronco or even an outboard. From what I have found is they range anywhere from $50 on Amazon to over $200 on specialty sites. Hope this helps and happy fun filled boating!!

  2. T. J. Stefanic says:

    Nicely presented FACTS to aid when looking for a used boat AND I’ve been boating the inland rivers for 60 years!!! Yes, I learned something today after reading said article, thanks !

  3. Richard A. Campbell says:

    You talked about the out drive oil reserve, I have two Mercruiser’s a 140 hp, and a 260 hp, neither one of them have the oil tank you talked about.. To check them you have to pull the upper vent cap,( screw in ) to see if it’s full.. and to check the condition of the oil, you leave the vent cap screwed in, but remove the lower drain plug.. Do this very carefully because oil will come out.. Keep a finger handy to plug the hole while you look at the cap.. It has a magnetic tip that should have some tiny metal flakes on it, but very many..! The oil may also be “foamy” if the owner used a synthetic oil, so that is NOT always a way to tell if it has water in it.. You have to know what you have, what oil was used, and know what you are looking at, befor it is any real value to you…

  4. Patrick T McCormick says:

    Looking to get back into boating after a few years without one. Been Jonesing ever since.
    Great article as I cannot afford new and will use these tips to curb my enthusiasm.
    Thank you

  5. Terrie says:

    I think this is a really helpful article for boaters who already know what they want to buy. It’s so easy to overlook things when you think you’ve found the boat of your dreams! There are so many options out there for fun on the water. It’s great if you’ve already decided what you want to buy, but what if you’re still trying to decide? We are offering a free guide on our site,, that might help potential boat buyers find exactly what is right for them. Check it out, if you’re not sure yet what you want to buy or what the pros and cons are for different types of boats.

    • chip says:


  6. Ella Dubusky says:

    We have a 1995 Bennington Pontoon 280L in excellent condition for sale. We are having difficulty pricing it. Can you advise us as to where or how to receive that information. Thanks. . .

  7. Brendan Connolly says:

    Hi. I’m looking at a 17 foot 2011 Lowe (unknown model) bass fishing boat with a 150 hp Mercury outboard engine and wireless trolling motor. The boat has a lot of bells and whistles, including custom seats from West Marine, fish finder, compass, fishing pole holders, etc. it has low engine hours 500-1000 from what I recall. Is there any issues with these boats? How does their haul hold up? Condition seemed pretty nice per the guy selling he only used in fresh water and the previous owner also had in fresh water. I did notice a marina sticker that’s on the Connecticut river which is brackish water.
    What recommendations would you advise? I asked about testing it out in a local lake and he seemed hesitant but I could follow up about that.
    He’s asking 6300. What’s a good base price for these things?