A Mechanic’s No-Nonsense Guide to Boat Inspections

I’ve been wrenching on boats in South Florida for about 15 years now, mostly around Miami and Fort Lauderdale. And let me tell you, I’ve seen it all. It’s funny—people are religious about changing the oil in their car, but they’ll let a $100,000 boat sit for a year and just hope it starts. That’s a good way to get stranded off Stiltsville with a dead engine and a storm rolling in.

A proper boat inspection isn’t just a checklist; it’s a habit. It’s what separates a smart captain from the guy calling me for a tow on a Saturday afternoon. This isn’t just about keeping the boat running. It’s about keeping you and your family safe, protecting your money, and making sure your day on the water is actually enjoyable, not a series of unfortunate events.

I’m going to walk you through how I look at a boat, whether it’s for a pre-purchase inspection for a nervous first-time buyer or the quick once-over I do on my own rig before heading out. We’ll cover:

• Why you can’t afford to skip inspections.
• The deep dive you need to do before buying a used boat.
• The simple checks that will save your weekend.
• The safety gear that the Coast Guard—and common sense—demands.
• When to put down the tools and call a pro like me.

So grab a coffee. Let’s talk about how to really look at a boat.

1. Why You Can’t Afford to Skip Inspections

Let’s get one thing straight: checking your boat isn’t just some chore. It’s your first line of defense against things going sideways. I see guys who think “it was running fine last time.” That’s famous last words in the marine world. A ten-minute check can save you from a ten-thousand-dollar engine repair.

Protecting Your Wallet and Your Peace of Mind

Your boat is a huge investment. Regular inspections keep it from slowly falling apart. Catching a small fuel leak or a bit of corrosion early is a cheap fix. Ignoring it can lead to a fire or a seized engine. When it comes time to sell, a boat with detailed maintenance records always fetches a better price. Buyers can smell neglect from a mile away.

Knowing when to inspect is just as important as knowing how. I break it down for my clients like this:

• Pre-Purchase Inspection: This is the big one. The deep, forensic dive before you hand over any money.
• Pre-Trip Check: A quick but critical 5-minute walk-around before you untie the lines. Every single time.
• Seasonal Inspection: When you’re pulling the boat for winter or getting it ready for spring. This is when you go deeper.
• Post-Event Check: After you’ve run aground (it happens), hit something, or been through a big storm. You gotta check for damage.

Making this a habit is what keeps you on the water and out of my repair shop.

2. The Pre-Purchase Inspection: Don’t Buy Someone Else’s Problems

Buying a used boat is the biggest gamble most people will take. You’re buying a machine that lives in a corrosive, unforgiving environment. A little due diligence here will save you an unbelievable amount of grief. Last year, a guy named Ray almost bought a slick-looking Sea Ray 260 Sundancer. The owner had it all shined up. I came along, did a “tap test” on the transom with the handle of a screwdriver, and it sounded dead—like tapping on a wet sponge. The core was rotted. I saved him from a $15,000 repair job.

Here’s the mental checklist I run through. I put it in a table for you.

What I’m Checking	What I’m Looking For	Red Flags (Walk Away or Negotiate Hard)
Hull & Deck	Cracks (especially around fittings), blisters, uneven gelcoat repairs.	Soft spots on the deck or transom, a dull thud from the “tap test,” major stress cracks.
Engine(s)	Corrosion, oil or coolant leaks, frayed belts, worn hoses. Must do a sea trial.	Unusual noises (knocking, grinding), smoke, overheating, stiff steering or throttle.
Running Gear	Propeller condition, shaft straightness, cutless bearing wear.	Dented or bent props, excessive “play” or wobble in the propeller shaft.
Electrical System	Corroded wires or connections, function of all lights, pumps, and electronics.	Flickering lights, pumps that don’t run, a messy “spaghetti” of unlabeled wiring.
Plumbing	Leaky thru-hulls, cracked hoses, functional seacocks.	Hoses that aren’t double-clamped, seized seacocks, any signs of leaks in the bilge.
Paperwork	Clear title, current registration, maintenance records if available.	A missing title, mismatched hull ID numbers, a seller who is vague about the history.

For the engine, especially on newer or bigger boats, it’s worth every penny to hire a certified marine mechanic. If it’s a diesel, get a Marine Diesel Engine Repair specialist. We can pull engine data, do compression tests, and spot things an amateur would miss. It’s the best insurance you can buy.

3. The Everyday Watch: Routine Checks That Save Your Bacon

Alright, so you own the boat. Now you gotta keep it from falling apart. This is all about simple, repeatable habits.

Before Every Trip: The 5-Minute Walk-Around

Before you even turn the key, do a quick lap. Check the bilge—is there any water, oil, or fuel in there that wasn’t there before? A clean bilge is a happy bilge. Glance at the fluid levels. Pop the engine cover and look at the belts and hoses. Anything look cracked or loose?

Most importantly, double-check your safety gear. This isn’t optional. It’s the law, and it’s just plain smart.

• PFDs (Life Jackets): Make sure you have one USCG-approved jacket for every person on board, and that they’re easy to get to.
• Fire Extinguishers: Are they charged? Is the needle in the green? Can you get to them in a hurry?
• Flares & Distress Signals: Check those expiration dates. An expired flare is a useless piece of cardboard in an emergency.
• First Aid Kit: Is it stocked?

Monthly and Seasonal Chores

Once a month, go a little deeper. Check your battery terminals for corrosion and make sure they’re tight. A loose battery connection is a great way to get stranded. Top off fluids and keep an eye on your engine anodes.

And when it’s time for winterization or de-winterization, don’t cut corners. Draining the engine block properly or remembering to put all the drain plugs back in before launch seems obvious, but you’d be surprised how many engines I’ve seen cracked from ice or boats sunk at the dock on the first day of spring.

4. Playing by the Rules: Safety Gear and Compliance

The Coast Guard doesn’t play around, and neither should you. Their rules are there for a reason: to save lives.

You need to have the right number and type of PFDs, fire extinguishers, and visual/sound signals for the size of your boat. Check the USCG regulations, but also your state rules, as they can be stricter. Navigation lights have to work—all of them. And if your boat is under 26 feet, you should be wearing your engine cut-off switch lanyard anytime you’re on plane. It stops the boat from doing the “circle of death” if you fall overboard. It happens.

Don’t let a safety violation ruin your day with a hefty fine, or worse, turn a good day into a tragedy.

5. Beyond the Boat Itself: Trailers and Moorings

Your boat inspection doesn’t stop at the boat. Don’t forget the stuff that gets it to the water and keeps it safe at the dock.

I’ve seen more weekend plans ruined by a busted trailer bearing on the side of I-95 than by engine trouble. Before you tow, check your tire pressure, test your lights and brakes, and make sure the safety chains and winch strap are solid.

At the dock, look at your mooring lines. Are they frayed or chafed? Is that dock cleat secure? Are your fenders in the right spot and properly inflated? I saw a beautiful Intrepid get beat up against a piling at Dinner Key Marina during a squall because the owner used cheap, skinny dock lines that snapped. Don’t be that guy.

6. When to Holler for a Pro

Look, I’m a mechanic, and even I know my limits. You can and should do your own basic inspections. But there are times when you need to call in a professional.

If you’re looking to buy a boat, a marine surveyor is your best friend. They produce a detailed report on the entire vessel’s condition, which your insurance company will probably want anyway.

For engine trouble, especially anything complex, get a certified mechanic. We have the diagnostic tools and experience to figure out if that weird noise is a simple fix or a sign your engine is about to give up the ghost. Trying to be a hero on a complex Marine Engine Repair can turn a $500 fix into a $15,000 replacement.

Conclusion: Your Boat’s Best Friend is You

So there you have it. A proper boat inspection routine isn’t magic. It’s just paying attention. It’s about being proactive instead of reactive. It’s what gives you the confidence to head offshore knowing you’ve done everything you can to ensure a safe return.

Your boat is your escape. Keep it safe, keep it reliable, and it will pay you back with incredible memories. Now go take a look at your boat.

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FAQ: Questions I Get at the Dock

Here are a few questions I get asked all the time.