What tools do you actually need to inspect a boat?  Well, that depends on how deeply you want to understand the boat’s construction, its condition and what your relationship is with the boat.  Inspecting any boat can be done with the minimum of tools and a few basic skills.  However, the deeper an understanding you wish to have of the boat’s construction and condition, the more tools and skills you are going to need.  In this blog we are going to look at what tools you are likely to find in the marine surveyor’s toolbox.

If you are a prospective boat buyer sifting through the numerous boats on offer at your local marinas, all you really need is a notepad and pencil, a good torch, a straight edge and a camera.  You probably already have all of these things at home and need not spend any money on extra tools to start taking notes and making observations to weed out the unsuitable boats on offer before you choose ‘the one’ and instruct a marine surveyor.

If you are already a boat owner you probably have a modest tool kit on board which should cover all of your boat’s routine maintenance tasks and be suitably equipped for any unexpected tasks.  This tool kit is likely to be quite personalised to the style and age of your boat and to your technical ability.

By contrast, a small craft marine surveyor needs a well equipped toolbox with the right tools to cater for the wide range of vessels which make up his work.   The range of tools will vary according to the types of boats he specialises in and those that are predominant in his local area.  This all needs to be stowed into a small enough package that he or she can carry it a reasonable distance from the car to the vessel.

I started surveying in 2008 and whilst my toolbox has grown in capability it has stayed largely within the same space envelope.  Along with showing you the equipment I take on every survey, I have put together a really useful resource to help you get equipped for small craft surveying which I will signpost you to later on.

So then, let’s get down to business.  I have separated my toolbox out into five key elements and have added pictures with a Genius link for each item which will take you to the Amazon store of your region. As an Amazon Associate I earn from qualifying purchases.

1. Marine Surveyors Toolbox – Essential Kit

This is probably the largest section of my toolbox and contains a whole host of everyday basics such as a decent torch, work lamp, camera, plumb lines, magnets, chalk, spray paint and batteries to name but a few.  The range of basics you need is very much dependant on the type of work you do.

A decent torch has to be one of the most important non-tool bits of kit in your toolbox.  The deep recesses of most boats tend to not have any lighting and you will need a reliable source of light that works way better than your smartphone’s built in light.  I’ve been fan of Maglite torches since my time in the military and I value their rugged construction and bright light, especially as they are all now LEDs.  Torches are very much a personal choice, mine is a 2 C cell torch with a knurled grip which I find works best for me when my hands are either cold, wet or both.

To go with the torch is a standalone work lamp which can provide more area lighting when working underneath vessels or in larger unlit rooms.  My Ryobi work lamp runs on the Ryobi One Plus 18v rechargeable lithium ion batteries which also power a wide range of other tools.  It has got a useful hook base so you can hang it off beams or use a lanyard.  I have found the run time to be about 4-5 hours on one charge which is more than enough for most survey jobs.

A decent ladder is an essential piece of kit which should always be in your car.  Most good brokers will have left a ladder attached to the vessel to facilitate buyer viewings but if you’re doing insurance work or need to have a close look at the topsides of a deep draft yacht you’ll need a ladder.  I’ve had my 3.2m, 11 rung Telesteps telescopic ladder for over a decade now and it has been perfect for my work. As always there are plenty of cheap options out there aimed at the occasional home DIY market, but if you want something sturdy that won’t give you the wobbles when you’re 3m off the ground then buy a quality ladder such as Telesteps.

One of the big investment pieces you will need quite early on is a decent camera to record your findings.  You may already have a decent DSLR camera or be happy to use your phone as modern phones do have very capable cameras.  I prefer having a dedicated camera and keeping my phone as an emergency backup should the battery die.  I’ve been using Olympus Tough cameras since I started surveying and my first one served me really well for a decade.

I am now on my second one, the uprated Olympus Tough TG-6.  I wear it around my neck on a lanyard so I can pull it out and take a picture with one hand and I’m not worried about dropping it in the bilge as it has a lanyard around my neck and is waterproof and shock proof.  The picture quality at 12 mega pixels is excellent and it can add GPS location data if that is needed in any insurance work you do.

Of course with a lot of my kit being battery powered, don’t forget to have a ready supply of batteries in your toolbox.  In my case that means AAA, AA, C and 9V batteries for my various tools.  I have always preferred Duracell Ultra batteries and they used to come with a useful inbuilt charge tester so you could quickly find the flat battery!

2. Marine Surveyors Toolbox – General Tools

Now let’s have a look at the wide range of general tools which get used on most if not all of my surveys. This includes several measuring devices such as flexible steel and tape measures for measuring length, beam and draft of the hull. I have a 30m tape measure for measuring the length of a vessel, this one is easy to wipe clean with some rag after using it in a dry dock where the floor is seldom dry!

I also have an 8 meter steel tape measure for taking draft and beam measurements and its stiff design makes it great for measuring fuel and water tanks.

For measuring propshafts, rudder stocks, anchor chain and standing rigging I have found a vernier gauge to be ideal. It’s a surprisingly accurate device once you master the skill of reading the scale and has both metric and imperial measurements on it, perfect for working on old boats.  I also have a small micrometer which gets used occasionally for taking specific measurements on small items.

A pit depth measuring tool is essential for assessing pitting on a steel hull.  I have been using a Mitutoyo dial depth gauge since 2013  and really like its easy to read dial and shape which fits nicely in the hand when crawling underneath old narrowboats.  It has a 0-10mm range which is ideal for pretty much every situation I have needed it for.  My gauge has been discontinued but the link will take you to the nearest equivalent.

As for hammers, I carry three in my toolbox – a  lightweight hammer for percussion testing FRP hulls, also known as the toffee hammer, a heavyweight hammer for barges and narrow boats and a soft faced hammer for hitting everything else where I don’t want to leave a mark.

A Selection Of Surveyor's Hammers

A Selection Of Surveyor’s Hammers

Every surveyor will have their preferred style and brand of scraper.  I have found the Bahco silicon carbide scrapers to be very effective at clearing old antifouling away from FRP hulls for taking moisture meter readings.  It has a good grip and the blade can be removed and rehoned on a traditional wet stone. I’ve also swapped the blade for a shorter blade which gives me better control when scraping coupons.

For light duties clearing slime or marine growth from a hull for thickness checks I use a Stanley Dynagrip filling knife which has just the right amount of flexibility in the blade and a comfortable grip for prying into corners, behind seacocks and a multitude of other uses.

Surveyor’s Top Tip – A useful tip is to round off the corners of your general purpose scraper to prevent it from digging in and leaving marks where you shouldn’t.  A normal metal file will do for this or find an out of the way piece of concrete and use that to round them off!

A very useful tool for the small craft surveyor is a battery voltage drop tester.  This is used to check the voltage of a battery before and after a high resistance load is applied to gain an understanding of the battery’s condition.  This is a simple to use, robust piece of equipment which gives confidence in the state of the batteries.

A set of spanners is essential to get the battery clamps undone so the batteries can be tested individually.  My set of reversible Bahco spanners has 12 sizes of spanner from 8 to 19mm, all with reversible ratchet heads and comes in a great little storage bag, perfect for the car as well as the toolbox!

Another really useful tool is a decent multimeter which I use to check for continuity between anodes and propshafts and other elements of the bonding system.  There are plenty of cheap multimeters on the market, some obviously better than others, but this is one area where quality is worth paying for.  I have had my Fluke meter since before I took up marine surveying and it has never let me down.

Many surveyors shy away from anything other than the most basic of engine checks as part of their survey routine.  I always try and find out as much as a I can from an engine, especially if I am unable to start it during the survey.  Testing the engine coolant is a quick and easy test which can teel you a lot about the condition of the engine and how good the servicing has been.  Finding that the complex and expensive engines of your client’s dream boat are filled with nothing more than plain water will greatly enhance your reputation.  Coolant plays an important role in protecting against frost damage, but an even greater role in corrosion protection, which given the variety of metals present in any engine, is essential.  Testing the concentration of coolant and the level of frost protection it provides in the engine is very useful data and my Gunson 77105 coolant tester is an ideal piece of kit.

Having a telescopic angled mirror is a really useful tool for looking at the reverse side of engine mounts, the top edge of rudders, bottoms of keels and for finding the serial numbers on engines which are nearly always on the least accessible side of the engine!  There are plenty to choose from but I went for a Bahco mirror as I have always rated their build quality.  And no, its not cracked, that’s the tree branches above it!

The last item on my general tools list is a quality jewellers loupe or eyeglass.  Like most people, as I age my ability to focus on things very close up has been steadily decreasing so I find a small magnifying glass that fits in my pocket to be really useful. My jewellers loupe has a 10x magnification, a triplet lens and comes with a tough little leather case.  It is most certainly not something I needed back in 2008!

Kite Optics 10x Jewellers Loupe

Kite Optics 10x Jewellers Loupe

3. Specialist Kit For FRP Surveys

In this section we’ll look at the specialist tools I have in my marine surveyors toolbox for surveying FRP hulls.  When it comes to doing a moisture survey on an FRP hull, I have been using a Tramex Skipper Plus moisture meter since I started in 2008.  This is a great entry level tool to get you going in this line of work.   Its simplicity is its greatest strength and it makes a quick moisture survey very easy to undertake with one hand.  It is also ideal for recording moisture levels in the deck alongside deck fittings.

I then added a Sovereign moisture meter to my tool kit in 2012 which offers greater capability.  I find them both equally useful as they do work in slightly different ways and each has their pros and cons.  They sit in quite different price points though so you may prefer to start with the Tramex and see how you get on with that alone.  As with any measurement tool, the results are just the first stage of the moisture survey, it is the interpretation which matters and adds value to what you do for your client.

Sovereign Quantum Marine Moisture Meter From A Marine Surveyors Toolbox

Sovereign Moisture Meter

Tramex have recently launched an updated version of the Skipper Plus which looks really promising and offers increased capability over the original version.  I’ll be looking to get my hands on one soon and will do a tool review video when I do so keep an eye out for that.

At the other end of the cost spectrum for equipping yourself to undertake FRP boat surveys is some humble litmus paper for testing osmotic blisters.  I use a general purpose universal litmus paper which gives a colour based reading for all pHs from 1 to 14.  This gives a reassuring confirmation that the contents of a blister are indeed acidic.

Surveyor’s Top Tip – Make sure you wear safety glasses when you pop osmotic blisters as the contents can be under quite high pressure and with a typical pH of 3, its going to really sting your eyes.

4. Marine Surveyors Toolbox – Iron, Steel & Aluminium Surveys

Getting equipped for ultrasonic measurement of metal hulls requires a fairly substantial investment.  There are broadly speaking two main choices of ultrasonic thickness meters for the aspiring steel surveyor; the Cygnus range or the Tritex range.  I have been using my Cygnus 4 General Purpose meter since 2013 and have found it to be an excellent piece of kit, its only real limitation for me has been reading the LCD display in bright sunlight.  It gives consistent readings, sits easily in my left hand with my couplant bottle and scraper leaving my right hand free to take the readings.  The reading also has a signal strength or confidence scale on the left which lets you know when you have a good reading.

From what I have seen of the Tritex thickness meter at demonstrations given by Jon Sharland over the years, they offer a similar capability to the Cygnus in a slightly different package and are an equally popular choice amongst small steel craft surveyors.  I think it comes down to personal preference and whatever price deal you can get, including servicing and extra probe heads if you need them.

To go with the meter you will need a supply of ultrasonic couplant in your marine surveyor’s toolbox.  You can buy specialist ultrasonic couplant from your meter supplier but I have found general purpose medical ultrasound gel to work just fine.  You can get it in 5 litre jugs and if you add a pump dispenser then you have an easy resupply method when you finish the survey to top up the small bottles of couplant that come with your thickness meter.

Your thickness meter should also come with a small steel test piece, typically 10-15mm thick, to check calibrate your meter before and after a thickness survey.  I use the 3.5mHz 13mm probe which is rated as good for measuring in the range 2-150mm.  As mine came with a fairly chunky test block, I decided to enhance this capability and bought a set of 6 thickness test blocks ranging from 1.5 to 20mm to give me greater confidence in the meter and its ability to read below 3mm.  I also have a small piece of 8mm aluminium plate which I was given whilst surveying an Ovni yacht in France which is my aluminium calibration block.

Ultrasonic Meter Thickness Test Blocks

Don’t forget you will need to get your thickness meter re-calibrated every 12-24 months by the manufacturer.  This will mean sending it away for a week or so and it will return with a Calibration Certificate which is an important document should anyone challenge your findings.

Sometimes on older iron and steel vessels the condition of the outer plate is rough and it can be hard to get a good sample of readings as your probe needs a flat enough surface both internally and externally for the ultrasonic signal to reflect off.  In these situations it is appropriate to do a bit of linishing to grind flat a few spots using an angle grinder to help you get a flat enough surface.   I use an angle grinder from the Ryobi One Plus range which uses the same battery as my work lamp.  Coupled with some general purpose grinding discs it makes it quick and easy to get readings in areas of interest.

There is always a packet of Milliput two part metal epoxy putty in my marine surveyor’s toolbox.  When you are doing a metal hull survey in between tides, the Milliput is an insurance policy in case you hole the hull with your hammer.  You just mix up the two parts in equal quantity and stick it in the hole where it will set, hopefully preventing the vessel from sinking.  It doesn’t weigh much and I haven’t had to use it yet, but it is very reassuring to know it is there in case I need it.

Surveyor’s Top Tip – The first time you do a tidal survey just keep an eye on the tide coming in, as it always seems to come in much quicker than it went out!

5. Wood Surveys

Like most general small craft surveyors, wooden boat surveys make up less than 10% of my workload.  I have always enjoyed being commissioned to survey wooden boats as they are fascinating vessels, mostly with great stories to tell and are, by and large, quite beautiful to my eyes.  Of all the small craft survey disciplines though, wooden boat surveys are the most challenging as every piece of wood is important to the overall strength of the hull as wood is not a largely homogenous such as steel or FRP.

The three tools most important to this type of survey are your lightweight hammer I mentioned earlier for percussion testing the wood, a small spike for probing any soft wood and a moisture meter specifically for measuring wood.  In my marine surveyor’s toolbox is an old Stanley screwdriver with a small solid hard plastic handle and a tip that I have rounded off.  It wants to be sharp enough to penetrate soft wood but not so sharp that it marks sound wood or varnish.  The hard plastic handle also acts as a mini hammer for tapping in hard to reach areas.

Surveyor's Wood Spike

Wood Spike

Surveyor’s Top Tip – I use an old cork to cover the end of my spike as catching it under a fingernail whilst rummaging around for tools is quite painful.

The Protimeter Mini General Purpose wood moisture meter is a great little tool which gives a percentage moisture reading when the two metal spikes are pressed into the wood.  Use it for probing along the bases of wooden bulkheads and other structural wood.  It comes out of the toolbox during a lot of surveys as most FRP boats are built with wooden bulkheads glassed into the hull and the interior of almost all vessels is typically built around a wooden frame attached to the hull.


I mentioned a great resource earlier which I think you will find really useful.  Using Kit.Co I have put together a Kit List for each of the sections we have discussed here.  In there you can find a brief description of the product, why I like it, what it adds to my surveying and why it is in this Marine Surveyor’s toolbox.  These are all tools that I use in my day to day marine surveying work and are based on my personal experience gained since I started surveying small craft in 2008.  You can find all my kit lists here: https://kit.co/WhiteHatMarine

If this blog was useful for you and you learnt something new, why not buy me a beer by visiting www.buymeacoffee.com