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.
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.
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.
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.
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.
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.