On the most vital instruments on your boat is your compass. When it comes to buying a new one the market can be a bit of a minefield.
There’s a wide range of models available and when you add the fact you can choose between different mounting systems and card types, it can all get a bit overwhelming.
To help you narrow it all down we have created this comprehensive marine compass buyer’s guide.
For our top 5 picks at a glance, view the table below. For in depth reviews on each of our top rated boat compass choices – keep on reading.
Best Boat Compass – Top Rated Picks
Marine Compass Buyer’s Guide
Choosing the correct boat compass
As we mentioned above, choosing your marine navigation equipment can be difficult. After all, which is the best boat compass for your needs?
The size and type of compass and mount you need are the most important considerations.
You should also not fall into the trap of thinking that your GPS system is suitable a replacement for a compass.
The problem with a over reliance on GPS is the basic fact it cannot give you a real time heading, taking into account current, wind and boat speed. For that you need a compass.
The size dial of compass you go for is often dependent on the type of boat you have (and the mount that you intend to use).
Generally speaking, compass dials range between 2 and 6 inches.
Larger boats require larger dials, if only for the fact you will more likely travel longer distances. Who wants to stare at a tiny dial readout for hours at a time?
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How does the small boat compass work?
Stripping it all down to physics lesson 101 the marine compass works via the magnets contained inside; they naturally seek out Earth’s magnetic north.
For a more detailed explanation, you need to understand that most marine compasses actually have two sets of magnets inside the unit.
The one set of magnets is “balanced” to seek out magnetic north. (Believe it or not this is variable. At the moment earth’s north polarization is close to Ellesmere Island, Canada.)
Nautical charts show the difference between the true north and magnetic north and this is called the variation.
The other set of magnets you will find in a small boat compass are the corrector magnets.
These are designed to correct the deviation that occurs on the compass reading because of all the other electronic equipment most modern vessels have on board.
These corrector magnets are attached to brass rods which are installed in the base of the compass. These are adjustable and allow the user to compensate the compass card to account for the interference.
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The Different Types of Boat Compass
Size of the marine compass
The size of the marine compass is a reference to the “apparent” diameter of the reading card.
The word apparent is used because we are talking about the diameter has viewed under the magnifying lens effect of the compass cover dome.
As we mentioned earlier, sizes generally range between 2 and 6 inches. However, common sizes include; 2″, 3″, 3-3/8″, 3-3/4″, 4-1/2″, 5″, 5-1/2″.
The larger the compass the easier the numbers will be to read. A larger compass will also be more stable in rougher seas.
We told you there were a few variables when it comes to buying the best marine compass. Once you have set on the right size, there also various card types to choose from.
Flat card compasses are the instrument of choice if your line of sight towards the compass is often from above. Vessel configurations such as the sailboat pedestal and center console powerboat installations fall into this category.
One of the biggest plus points of the flat card compass is the fact the numbers and graduation lines appear much larger that on other card types.
This optical effect is due to the card being further away from the compass dome cover, meaning the magnification of the readings is greater.
Front Reading Card
The most widely used boat compass style is the front reading card. In this configuration the card is dome-shaped. The readings are placed along the vertical edge of the card so that they are positioned closest to the helmsman.
Front reading cards are best suited to situations where the compass is mounted close to your line of site. From a level perspective a flat card would be difficult to read.
Size is a variable here too. Front-reading cards often come in at under 3 inches in size.
The negative aspect of the front reader is that the magnification is minimum, (the card is curved towards the dome cover). This makes them more difficult to read.
Dual Reading Card
The third option available is the dual-reading card. As the name suggests the card incorporates aspects of both the flat-reading and front-reading card design.
This makes the dual reader a good choice for those that have a viewing angle that is constantly changing. In other words if you are up and down and out of your seat like a yo-yo as you sail, you might want to consider a dual reading card.
They are most commonly found on larger powerboats and will be positioned at eye level.
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Installing Your Marine Compass
Finally there is the important issue of installing the compass. For this you have 4 main systems; the bracket mount, a flush mount, bulk head mount or binnacle mount.
Let’s take a closer look at each.
The Bracket Mount
Bracket mounted marine compasses are easy to install and give you ample choice for positioning.
The compass bracket can be fixed into any available space, and the fact it doesn’t take up much room only increases the versatility. The compass is then simply screwed onto the mount.
The most stable method of attaching your compass to the boat is the flush-mounted method.
However, this does involve cutting a clearance hole for the compass to sit inside the mounting surface.
The result is obviously aesthetically pleasing, and is the preferred method for boat builders, (it could well be that your boat already has the clearance hole, meaning you old need find a replacement compass of the same dimensions).
The downside of the flush mount is the fact it takes longer to install.
This goes beyond the actual cutting of the surface. The compass needs to be level and aligned with the keel of the boat within a few degrees. If not, you will the unit will be installed with in-built error that is difficult to account for.
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Bulk Head mount
When a boat compass has been installed via the bulkhead method, it basically means it is flush inside a vertical surface. The pros and cons of this mounting system are the same as the flush mount compass.
You will often find binnacle mounted (sometimes called deck mounted) compasses on sail boats.
Here the compass is positioned within a cylinder which is then fixed to the top of the steering pedestal.
Surface mounting is another variation of this theme. Normally found on smaller boats, the base of the compass is fixed directly onto the surface of the console.
The compass itself can removed from the base.
Whether binnacle style mounted or simply surface mounts, the configuration normally involves the compass base being attached to the surface of choice via screws.
One of the down sides is the lack of versatility and the fact the surface mounting system takes up more space when compared to other methods of attaching your compass to the boat.
Marine Compass Reviews – Our Top 5 Picks
1. Ritchie Hf-743 Helmsman (Best Flush Mount)
The Ritchie HF-743 Helmsman CombiDamp dial compass is our number one choice flush mount compass system for a number of reasons.
First off there is the dual reading card design. They call it the CombiDial, but the end result is just the same, no matter your orientation at the helm you will be able to view your readout due to the fusion of direct and flat card systems.
Measuring in at 3 3/4″ (94mm) the CombiDial card is a good size that allows for clear visibility.
However, the manufacturers have gone a step further to ensure you can still read your compass in low light conditions.
The Ritchie HF-743 has a built-in 12 volt green illumination display. This allows you to see exactly what your compass is reading at night.
Build quality is of the level we have come to expect from Ritchie.
The compass features a scientifically matched sapphire jewel and hardened steel pivot dial movement. Not only does this increase the reliability of your readings, the unit is designed to withstand tough nautical conditions.
The system also utilises powerful Directive Force magnets for fast heading lock-on.
The built-in compensators are adjustable of course, making it easy to counter the HF-743 for deviation.
Dimensions on the flush mount come in at 4″ (102mm) (so make sure you measure up on that first).
To top it all off, the Ritchie Hf-743 is backed by an extremely generous 5 year warranty. The manufacturers are clearly confident you will not need their assistance for a long time after purchase.
Clear display, superior build quality and an effective CombiDial card system for increased clarity and versatility. What more could you want from your flush mount boat compass? Our number one choice for good reason.
2. Garmin (Silva) 85E Sailing Compass (Chrome Flush Mount)
An alternative on our top pick Ritchie Hf-743 is the Silva 85E.
This too opts for a flush mount system making it extremely stable once fitted into place, (assuming you know what you are doing with the power tools to install it correctly).
A benefit of the Silva 85E is the fact it has a flat bottom. This may seem trivial however, it means you do not have to cut such a deep hole when fixing the compass into place.
The card style is strictly flat, so you do lose out on the excellent CombiDial features of the Ritchie. However, the flat style configuration does offer increased magnification on the readings.
The compass card on the Garmin (Silva) 85E is designed to suit high speed as well as rough conditions while out on the water.
The unit also has a clear, in built, 12V back lighting illumination system to ensure clarity of readings should the going get tough, (and dark).
There is also an in built memory ring for setting and maintaining your course.
And let’s not forget the all important dimensions. On the Silva 85E you are looking at 67mm height and 120mm width.
Finally, not to be outdone (in comparison to the top pick Ritchie), Silva provide a competitive 5 year warranty.
For those on a more restrictive budget, the Garmin (Silva) 85E Sailing compass may well fit the bill.
While it doesn’t have the features and build quality of our top pick Ritchie HF-743, it remains a worthwhile option.
3. Ritchie Navigation Explorer Compass, 2 3/4-inch Dial (Best Bracket Mount)
The Ritchie B-51 Explorer bracket-mount compass is our top pick for this configuration because it offers a bucket load of great features.
Like the HF 743, the Navigation Explorer utilises a scientifically matched sapphire jewel and hardened steel pivot dial movement.
Ritchie have also included those powerful Directive Force magnets we talked about above. Highly sensitive, the magnets are constructed so that fast heading lock-on is possible.
The compass also features built-in compensators that are easily adjustable for deviation.
Ritchie have opted for a direct read dial on this model for optimum line of sight visibility. The measurements of this come in at 2 3/4″ (70mm), (which might be on the small side for some tastes and requirements).
However, for smaller vessel owners the Navigation Explorer has proven a big seller, with Ritchie stating it as being their most popular and versatile small boat compasses to date.
Again as with the HF 743, this bracket mounted option has a built in 12v night light for increased illumination when the sun goes down.
On the subject of the bracket, this is well built and simple to fix to a surface of your choosing.
Finally you have that competitive 5 year warranty cover for extra peace of mind.
Richie build quality with the top features you can expect from this popular brand. If you’re after a bracket mounted boat marine compass at a competitive price, this is the one to buy.
4. HDE Compact Marine Boat Compass with Bracket Mount
The HDE Compact Marine Boat Compass is a worthwhile Bracket Mount option for those that need a functional, easy to install device that won’t break the bank.
However, the low cost does mean the compass does fall short on our top pick Ritchie by a big margin. It doesn’t have the build quality or the features to compete.
So why has it made our top 5 picks?
Well ease of installation really is the strong point on the HDE. The compass comes with a sticky mount pad that connects the bracket to the surface you choose, along with 2 Phillips screws. You can have the compass in position with minimum fuss.
Marketed by HDE as a go to option in case of emergency situations, the HDE compact marine can also be used for activities such as hiking and watersports.
As a versatile back up compass it really does fit the bill.
The HDE compact marine is a cheap small boat compass. For those that require nothing fancy, or would like an affordable back option safely stowed on board, this represents a worthwhile option.
5. SP-5C Ritchie Navigation Globemaster Compass (Best Binnacle Mount)
The SP-5C Globemaster Compass is our top pick binnacle mount option because it is both extremely elegant with superior performance all in one package.
The compass features a large 5″ (127mm) flat-card dial for optimum visibility from within the pedestal where it is designed to be fixed.
The unit is compatible with the majority of pedestal designs however you are still advised to contact the manufacturer should you have doubts with your own particular configuration.
The compass has a 71/4″ (184mm) base and like all the Ritchie manufactured models we have reviewed in this top 5 round up, comes complete with a 12V LED Green Night lighting display.
The unit is 100% repairable and also features a built in compensation.
There is of course the obligatory Ritchie 5 year warranty, offering you that extra peace of mind after you have parted with your hard earned money.
If you’re after a Binnacle mounted marine compass, Ritchie have gone and done it again with their SP-5C Navigation Globemaster. This is a sleek addition to any yacht in need of a such a navigational device. Highly recommended.