An essential tool for every sailor, the nautical compass should never be missing, under any circumstances. It is necessary to choose the right one for your boat, install it in the correct way, know how to read it perfectly and take great care of it. Poetically called - and not by chance - also the needle of wonders, the nautical compass, in its simplest, oldest and most home made version, consists of nothing more than a container containing water and a piece of metal. Nothing trivial, in short. And yet... and yet this simple object was the real keystone that revolutionized the world of navigation, and not only.
How does the nautical magnetic compass work? A bit of history
The nautical magnetic compass is based on the invisible force that is magnetism, that is, it guides us by identifying the magnetic field that connects magnetic north and south - which, as we will point out later, do not correspond perfectly with the two geographical poles, although they are very close.
We all know that magnets have the property of attracting certain metals towards them, primarily iron. But that's not all: the same magnets - if developed in length and free of impediments - also have the tendency to orient themselves according to the magnetic field, that is, bringing one end towards the south, and another towards the north. The classical magnetic compass exploits this principle, starting with a magnetized steel needle, and therefore sensitive to the magnetic field, which is placed on a pivot, in the absence of friction.
But who invented the compass? Well, like many fundamental discoveries for mankind, from the wheel onwards, we do not know the name of the true inventor. What we do know is that, most likely, the first examples of a nautical magnetic compass appeared in China. At first this object was used as a toy and nothing more, but soon people began to think about what an incredible contribution it could have had in the field of navigation: without the nautical compass, in fact, navigation in the open sea and across the oceans would have been completely impossible.
In addition to being simple and intuitive, it should be noted that, despite its irreplaceable power, the magnetic nautical compass is completely autonomous. It does not require power supply or technical maintenance, as it does not actually malfunction: in fact, it cannot break the earth's magnetic field.
It is therefore no coincidence that, even today, there exists changing according to the quality and technology of the chosen model. There are inexpensive nautical compasses produced by the best brands, designed for smaller boats. Plastimo, for example, has created the Offshore 75 line, which is a nautical compass with a graduated conical rose designed for powerboats between 5 and 8 meters long. There are also nautical compasses of intermediate price, such as the highly appreciated Plastimo Horizon 135 compass, perfect for both sailboats and motor boats, built to be embedded on the horizontal shelf or directly on the column of the steering wheel. For those with a larger budget, there are advanced models such as Simrad's Precision-9 Compass, which gives mariners valuable information about heading and speed in conjunction with radar and autopilot, as well as jerk, roll and pitch data. The prices for a nautical compass, in short, can range from a few tens of euros to several hundred euros. And you, how much are you willing to spend to buy your new nautical compass?
How to protect and maintain your compass for effective navigation
As mentioned above, a magnetic nautical compass does not need special or heavy attention or maintenance, being in fact a very 'simple' object. To ensure a long life of the device, however, it is advisable to adopt some peculiar behaviors. First of all, as far as possible, it is a good idea to limit exposure to the sun. In addition to this, it is useful to preserve a 'neutral' magnetic environment around the compass, both during navigation and during winter storage. In case of bad weather, the compass should also be protected with an appropriate cover.
Installing a nautical compass: some valuable tips
The installation of a nautical compass is not complicated, but it should not be taken lightly either: there are in fact some steps to be considered carefully in order not to compromise the subsequent operation of the device and consequently end up off course.
The compass bearing line must be either coaxial or parallel to the axis of the boat. That's not all: as anticipated, the nautical compass must be mounted far from magnetic fields that could influence it. Its position, therefore, must be duly defiladed with respect to the instruments on board. Similarly, while sailing, no sailor should accidentally place his smartphone or vhf radio near the instrument: this simple inattention, in fact, could also concretely affect the result.
Once the installation has been completed - whether of a built-in compass or of another model - it will be necessary to check that the operation has been successful. To do this, it will be necessary first of all to read and memorize the value indicated by the compass about the line of faith, and then deactivate all electronic devices on board, removing any source of electricity (to do this, it will be sufficient to use the battery isolator). Once this is done, you will proceed to turn on only one electronic device of the boat at a time, while verifying that the value indicated by the compass does not change: if you notice a change, you can identify both the accessory guilty of the magnetic field, and the deviation caused.
Buy a Plastimo compass
On the pages of our e-commerce we host many different compasses. Among them, however, stand out those signed by the French brand Plastismo, not surprisingly one of the best known brands for the production of nautical compasses. This brand can count on more than 50 years of activity. To get an idea of the success of Plastimo nautical compasses, suffice it to say that, in 2013, the brand has reached the remarkable milestone of 3 million compasses produced.
In 1972 Plastimo brought to market the first ever model of magnetic compass built entirely with plastic products. Just two years later, in 1974, the brand could boast 20 different models of nautical compasses, which were 3 or 4 times cheaper than the compasses then on the market, made of brass or glass. If up to that moment Plastimo's market was limited to France and only to life jackets: from that point on, instead, the brand's fame became international, indissolubly linked to compasses.
Well: we've seen together how a magnetic nautical compass works, what are the models on the market, what are the prices and how best to mount the device on your boat. Now it's up to you: have you decided which compass to buy for your sailing or motor boat?