Physical specs
The size of a GPS module varies greatly. You can purchase small handheld GPS systems through to much larger mountable ones. The type you should choose depends purely on the purpose you want to use the module for. If you run a small boat and just want to sail it every now and again, then a small handheld GPS could be right for you, while if you own a bigger vessel and are planning more complex adventures, a bigger system would be appropriate. If you need to see intricate navigational details, then a GPS with a bigger screen is recommended.
Other physical considerations include the size of buttons on the GPS. If your GPS navigation system has small buttons, and you are planning on sailing in extremely cold weather, check that you will be able to operate the module whilst wearing gloves. For that reason you might also want to avoid some touch-screen modules. If you are opting for a handheld GPS navigation module then check if it has sufficient waterproofing and features rubber armour or another protection equivalent. This is because handheld systems are more likely to be exposed to the elements or dropped whilst on rough seas. Some handheld GPS systems feature ‘floatation’ casing, which means even if the unit goes overboard it can be salvaged.
Basic checks
Purchasers should check the listed battery life, as nobody wants to be left adrift after their GPS navigation system runs out of battery during a voyage. Some mounted GPS systems will be able to charge during operation, which might prove useful. Read reviews of the model you are interested in purchasing to gain a wider opinion on the user interface, which is crucial to operation. If the module seems difficult to operate, it is worth looking at other different systems which appear more user friendly. Marine GPS systems are designed to make our lives easier on board, so having to struggle with one which is complex and confusing to operate seems like a bad choice.
The level of processor power is another check to make, as the greater the processor power, the quicker the GPS navigation system will update your position and speed on the screen. More powerful processors allow the screen to be refreshed or redrawn quicker, as your boat moves. The connectivity of your GPS navigation module is a further consideration, to see how you can interact with it. A GPS navigation module with good connectivity can share information with other systems on the boat, as well as receiving radio and weather satellite readings. Most impressively, some units can interface with multi-function displays on your boat. If you want this last feature, check the details of both your boat’s displays and the model of GPS system you are interested in purchasing, to see if they are compatible.
Standard use
Marine GPS units have various different functions, but the most common, and primary one is navigation. GPS navigation modules are designed to paint an accurate picture of your surroundings. Whether that means helping you navigate through a bustling marina, or head in the right direction on the open seas, you can rest assured that your GPS system will highlight everything around you, so you can travel safely. It also means the chance of your boat colliding with another vessel is very low, because you will be able to see even tiny crafts on the screen, and change your course as appropriate.
Most GPS navigation modules come with GPS maps preloaded, often spanning various different countries. However, if you want to add GPS maps you will be able to, often via an SD memory card. A typical GPS navigation system will allow you to chart your route before your journey, making your trip a simple task of following the route you have set. They often feature a digital compass, and some models have satellite pictures to help guide you. Developments in screens have come a long way since GPS navigation systems were first introduced, and now even in bright light conditions most screens are very readable.
Specialist tools
However, GPS maps are not the only purpose these systems are used for. If you are interested in catching fish, you can purchase dedicated fish-finder modules. Or, better still, a combined GPS navigation and fish-finder system. There are many advantages of the combined module; for one, you will only need to set up and learn to use one piece of equipment. With fish-finder devices, the greater the screen resolution the better, because it makes your quarry easier to find and track.
Output power is an important consideration to make when buying a fish-finder. If you normally operate in water less than 300 feet deep, then a unit with less output power is acceptable. But if you are operating in deeper water, consider a system with over 500 watts of power, as well as dual frequency transponder capabilities. This is because you can operate the device at different frequencies to explore various depth levels. Some units feature the ability to rewind your sonar history, to keep track of your prey’s movements. Many units are equally capable in saltwater and freshwater, but if you operate only in one of the two, it is best to verify whether the model you are interested in is suitable.
The brands
There are a great many GPS navigation units available on the market, so it can be very difficult to pick one out. A popular and reliable range is the Garmin eTrex handheld GPS. These are reputable products, and the Garmin eTrex Vista HCx is one of the frontrunners. It is compact and lightweight, with a screen that most find very readable in all light conditions. It boasts an SD card slot and also a USB port, and can store up to 1000 waypoints and 20 routes. It is water resistant, although it does not have a ‘floatation’ coating. Most find the eTrex to be very user-friendly, and it uses a simple joystick control which you use to navigate the interface, and when you press it, it marks a waypoint on the map.
Another popular model is the Humminbird 597ci HD DI, which is a combined chart-plotter and fish-finder. This has a couple of very exciting features, including the ability to record and play back images, once you insert an SD card. It also allows you to manually set the depth range in one foot increments, meaning you can be incredibly precise. If you purchase a Navionics chart card you can access all manner of useful information, including port details and additional detailed cartography.
