Boat Inspection Checklist: For Buying A Boat

This article serves as a comprehensive guide to boat inspections, providing a detailed checklist to ensure you buy a vessel that is safe and seaworthy.

Boat inspections can be daunting, with so many components to check and potential issues to uncover. This guide aims to alleviate that stress, offering a systematic approach to ensure nothing is overlooked.

Leveraging insights from experienced skippers, marine surveyors, and the nearly 50 years’ worth of experience of our editorial team. Here is a thorough checklist that covers everything from the hull’s integrity to the functionality of electronic equipment.

We’ve broken down the inspection process into clear sections, making it easy to follow regardless of your boating experience.

At a Glance:

1️⃣ A pre-purchase inspection to ensure the boat is in the advertised condition.

2️⃣ An annual inspection that may be required by US Coast Guard regulations or as a safety consideration of your own.

3️⃣ For insurers to satisfy themselves regarding the risk and value they are taking on.

4️⃣ Whether required by regulations or not, a regular boat inspection is a good practice and may save you substantial costs later.

📝 What Should Be Checked Before You Buy A Boat?

If you have found the boat of your dreams and want to put in an offer, make it subject to the following suspensive conditions:

1️⃣ The boat passes a marine survey carried out by a suitably qualified surveyor.

2️⃣ All service and maintenance records are available (this will give you the security that the boat has been regularly maintained).

3️⃣ The boat has not been involved in any serious incident that caused major damage in the past.

4️⃣ To verify the accident history, past insurance records should be available. These can be used to check with past insurers to determine if it has been the subject of significant insurance claims (You may need a letter from the seller authorizing you to obtain these records).

5️⃣ That a full inventory is provided of all the items included in the sale (you don’t want to argue these issues once ownership has been transferred and payment made).

6️⃣ Examine the exhaust for holes, as this can allow water and exhaust gas into the interior space and bilge of the boat.

7️⃣ Find out the quantity, size, and type of fixed fire extinguishers on the boat.

🎱 Whether you’re using your boat for fishing, wakesurfing, skiing, diving, day cruising, or overnighting, remember to pack essential safety gear.

Once the above has been agreed upon, it is time to begin the boat survey.

What Is Checked During A Boat Survey (Motor And Sail)?

The items that are checked on a boat depend on the type of boat being checked. The items common to all boats (sail or power) include the following:

🚤 The Hull And General Integrity

The boat should be checked and the following confirmed:

1The boat sits level on the water with no listing to one side.
2The moisture levels in the hull material (wood or gelcoat) should be checked – these require special tools.
3Check the hull for evidence of damage or repairs.
4Check the condition of the gel coat on fiberglass boats to ensure there is no cracking or blistering.
5Inspect the transom to ensure that for wood rot and that it is solid and in good condition.
6Walk around the hull gently tapping a screwdriver handle against the surface – if the noise of the tapping changes to a “hollow thunk,” it may be an area that has become waterlogged and has lost its integrity.
7If the boat has a keel, it must run straight and true without warping.
8Check for leaks around the fuel tanks and fuel filters.

In addition to the checklist above, you’ll want to methodically go through each item below to ensure the general integrity is up to par.

If there is a rail around the side of the deck, check that it is secure, and there is no corrosion.

Ensure all the glass installed on the boat is in good order and does not need replacing. 

Check the deck for signs of damage and water ingress. Crawl and inspect for blemishes, cracks, and soft spots. Tap with a screwdriver handle to detect changes in sound. Pay attention to deck joins. Investigate any changes in sound to ensure structural integrity.

Check the integrity of the hull-to-deck joints, whether they are glued, bolted down, or glassed.

Make sure there are no gaps in the lockers, between the cabin furniture and the hull, or in any other compartments. These areas can be potential sources of water ingress if compromised.

Check the condition of all of the trim on the boat. If trim is missing or is becoming loose, investigate why this is happening.

The cause may be water ingress and possible wood rot behind the trim.

Check the condition of all boat hardware, ensuring (where appropriate) that it is in working order and remains tightly secured. The items to be checked include the following:

  1. Anchor windlasses and the electric motors, if fitted (test the windlass operation).
  2. Check the condition of the anchor and its chain.
  3. The cleats are secure and in good condition.
  4. If the boat has outriggers, check their condition and operation.
  5. If the boat has a tower, ensure it is securely attached and in good condition.
  6. If the tower is a collapsible model, test that it moves to each position.

Check that all hatches are in good condition. Things to check with hatches include the following:

  1. They are securely mounted, and the hatch hardware (hinges and latches) are not rusted.
  2. Check behind the mounting to ensure there is no wood rot.
  3. Check that all the hatches close easily and are not swollen due to water ingress.
  4. Check that all latches work.

🛋️ Interior Accommodation

The boat’s interior should be well-maintained, warm, and watertight.

Check for signs of water damage, such as water stains, peeling paint, corrosion, damp smell, and moisture in the cushions and carpets.

These indicators suggest potential leaks and require attention.

If these signs are present, you must find the reason, and if this cannot be fixed, it is time to cancel the deal.

When checking the interior, also check the following:

1The condition of the upholstery (this applies to external seating as well).
2The condition of the flooring.
3A damp smell.
4A leaking or non-working head.
5The operation of the freshwater maker.
6Check the sides of the cabins to ensure that they have remained watertight and that there is no wood rot.
7Check the operation of all faucets (and their water pumps) and the related drains.
8Check the security of crockery and cutlery.

🛞 Helm And Steering System

Check that the helm station functions correctly.

1Check the helm turns the rudder or engine (depending on what is fitted.)
2Check the condition of all instrumentation and ensure that the glass gauges are not cracked or misted.
3Check that the throttles move and the transmission can be selected.

📻 The Electronic Equipment Is Operational

All electronic equipment must be checked, which may include the following:

1Compasses (electronic and manual) work correctly.
2The radios work on differently tested frequencies – most harbor authorities are happy to respond to test transmissions.
3The autopilot switches on, aligns and adjusts the rudder position.
4The EPIRB and other safety communication devices work (this only applies if they are being transferred to the new owners).
5Global positioning systems (GPS) work.
6If a man overboard system is used, check that it is operational.
7If it is installed, check that the chart plotter works.

🚥 Navigational And Accommodation Lights

Check the condition of all the lights, firstly that the wiring is in good order, and secondly that they all work. These include all navigation lights for safety requirements and all interior lights.

⚙️ The Boats Engine 

Whether the boat has a gas-powered outboard, inboard, or diesel-powered power plant, it is very important to check on the condition of the engine(s).

If the engine overshoots or does not reach the manufacturer’s maximum rpm range, something may be wrong with it or the propeller.

Check the general condition of the engine housing and the engine itself.

  1. Check the general condition of the engine compartment (not outboards), which will give you an idea of how the engine has been kept.
  2. Ensure the engine compartment blower system works and the ventilation holes are not blocked.
  3. Ensure that the engines appear clean and free of dirt and oil stains.
  4. Ensure there are no obvious cracks in the engine mountings.
  5. Ensure there is no loose standing water or oil.
  6. Ensure there are no puddles of water or moisture.

Once you have satisfied yourself regarding the engine placement, you can begin more detailed engine checks.

  1. If it is a gas-powered engine, pull the spark plugs out and check the condition of the electrodes (some engine diagnoses can be made by studying the condition of the spark plugs.)
  2. Inspect the engine block, the exhaust manifold, and the oil sump for any leaking or any sign that they have been overheating (the condition of the spark plugs provides a clue in this regard.)
  3. Check the integrity of the engine exhaust.
  4. Check that there is no apparent rust on the engine mountings, propellor shaft, or other areas.
  5. Check the integrity of the engine mountings and ensure that the engine(s) are secure.
  6. Check all of the hoses to ensure they are in good condition – on an older boat, these may need to be changed.
  7. Check the belts’ condition to ensure they are not frayed and are set at the correct tension.
  8. Check that there are no oil and hydraulic fluid leaks and that the gaskets and seals are in good condition.
  9. Check the fuel injectors for leaks (stains) around the fittings.
  10. Check that the impeller housing(s) is/are intact.

Check the levels and condition of the engine fluids.

  1. Check the oil levels (with the dipstick).
  2. Check the condition of the oil (if it is grey, it may mean that water has been allowed to ingress the tank or there is a problem with the head gaskets).
  3. While the dipstick is visible, check it for rust or other damage.
  4. Extract gas (or diesel) from the gas tank(s) and visually check the condition.
  5. Check the fuel filters for sediment or other impurities that may be carried from the gas tank to the engine.

Check all of the fittings associated with the engine.

  1. Check the condition of the propellor and ensure each blade is in the correct shape and has not been damaged by grounding.
  2. Check the propellor for how much damage has been caused by cavitation. A propellor damaged by cavitation points to an incorrect trim (in outboards) or an incorrectly installed unit.
  3. Check the condition of the sacrificial zinc anodes and how much life they have before they need replacing.
  4. Check the propellor shaft bearings.
  5. Check the alignment of the engine and the propellor shaft.

Check the integrity of the wiring to and in the engine bay.

  1. Check that all wiring harnesses are intact and in good condition.
  2. Check that all electrical connections to the engine are in good order.
  3. Check that none of the wiring insulation is compromised and that none of the conducting material (copper or aluminum) is exposed.
  4. Check the batteries used to start the engines are clean, with no corrosion on the terminals.
  5. Check that the electrical cables that connect to the battery(ies) are in good order and tightly secured.

Start the engine and concentrate carefully to listen to how it runs.

  1. If the engine is, an inboard unit first run the blower for ten minutes before attempting to start the engine.
  2. With the engine started listen to the exhaust system to ensure it is intact and there are no exhaust leakages at the manifold or elsewhere.
  3. Start the engine and watch for excessive oil smoke.
  4. Check how much effort it took to start the engine.
  5. Watch and listen to the engine(s) at idle and ensure they run smoothly with no “lumpiness.”
  6. Listen to the engine while running and ensure no suspicious knocking sounds.
  7. Take the boat for a sea trial, during which you must continue listening to the engines (if it has more than one engine, switch off all but one at a time and check each one individually.)
  8. Check how the engines accelerate to ensure no hesitation or delay when the throttle is pushed flat.
  9. Run the engine(s) at full power for a long period and check for overheating.
  10. When you run the engine, listen out for excessive vibrations.

🛟 The Boats Safety Equipment

Check that all of the required safety equipment is present and in good order. If not, you can add this equipment.

You should, at a minimum, check that the boat meets the requirements for fire extinguishers as well as marine flare requirements.

🎓 Pro tip: If the previous owner hasn’t bothered with critical safety measures, then they probably haven’t bothered with basic maintenance either.

What Is Additionally Checked On A Sail Boat?

In addition to the common checks for power and sailboats, there are specific items that should be examined on sailboats:

Sails and rigging have an average lifespan of around ten years on a regularly used sailboat. Inspect the following components to determine if they require replacement:

1Check the condition of all the masts (they should be even, straight, and sound), booms, and other poles to ensure they are securely rigged and “true”.
2Examine every moving component (including all winches and masthead sheaves) to ensure they operate smoothly.
3Check all the blocks and welds have not been compromised.
4Check all the rigging for chafing and broken strands to ensure it is in good condition.
5Check the condition of the sails to ensure there are no damaged areas, chafing or other wear or damage.

🔑 Key Takeaways

Buying a previously used boat is a potentially risky venture where you may take over a previous owner’s long list of problems. To reduce the risk, before any papers are signed and money passes hands, it is worthwhile to have a formal survey conducted on the boat.

This will check the following:

  • The hull, deck, and cabins will be checked to verify the condition and that there are no waterproofing problems.
  • The engine will be checked to ensure it is in good condition, maintained, and is reliable.
  • All of the systems in the boat will be verified and signed off.


What Is Checked On A Boat Survey? 

Different aspects will be focused on depending on who is performing the survey.

The US Coast Guard

If the US Coastguard does a safety check on the boat, they will check that mandatory safety equipment is carried on the boat and that it is in a suitable location.

A Marine Surveyor

A marine surveyor will provide a detailed check that extends to all areas of the boat and drills down to minute levels, such as if electrical fuses are correctly marked.

The report they issue will categorize deficiencies under the following headings.

1️⃣ Critical – Items that are critical to safety that may result in an increased risk of fire, explosion, electrocution, injury, or loss of life.

2️⃣ Important – these items may make the boat unsafe to operate and cause the boat to lose control, suffer engine failure or take on water.

3️⃣ Not critical – These are nuisance items that are frustrating but do not compromise the vessel’s safety. If they are not corrected, that may ultimately cause a larger failure and substantial repair costs at a later stage.

4️⃣ Observation – These are notes for observation purposes only and may indicate that there is a better solution available.

What Is The Single Most Important Thing On A Boat? 

A few things are vital to the passengers and crew’s safety. These include.

How Often Does A Boat Need To Be Surveyed?

There are three circumstances when a boat should be surveyed.

A Pre-Purchase Inspection

Never buy a boat without it being surveyed to ensure it is sea-worthy and does not require substantial repairs.

If finance is being used to purchase the boat, the lender may insist on an inspection before they will release the funds. 

An in-depth inspection ensures that the boat is in the exact condition described when it was advertised.

Regular Ongoing Inspections

Boats carrying more than six passengers for hire need annual inspections. Inspect your boat annually for seaworthiness and to identify potential problems. This may not be the classification of your boat, but it’s good to keep it seaworthy.

For Insurance Purposes

They may insist on an inspection when the boat is transferred to a new insurance carrier. This will serve several purposes.

The insurers will be able to identify any existing damage (pre-existing condition)  that they will exclude cover for until repaired.

The survey should uncover any underlying problems with the boat that warrant repairing or upgrading to return it to a safe operating condition.

The boat has all of the safety and other systems required by state or federal regulations. This is important for many reasons, including a lower chance of an insurance claim and a reduced liability risk by ensuring the vessel was not being operated in a dangerous state.

Insurers will be able to assign the insured value of the vessel and ascertain whether the vessel is in a good enough condition to be insurable.

I’m the founder and chief editor here at Sailing Savvy. I spent a decade working as a professional mariner and currently, I mix those experiences with digital publishing. Welcome, and I hope that we can be the hub you need for safe passage.