Handheld chart plotters are becoming more and more popular, and so more affordable. But are they worth it?
A handheld chart plotter can be invaluable when eyeballing into a strange harbour, but with prices up to £700, you should be sure of your needs before you invest. There are plenty of ‘added value’ features in many of the devices on the market, but there are a few basics to look out for before you make your purchase, such as does it help you navigate?!
Power
A handheld set has a built-in power supply. Many sets use a mobile phone style battery. While these batteries can power for up to 16 hours, they will run flat at some point. You could carry a spare charged battery, but they are expensive. So a better option would be to buy a set which uses AA size cells. This way, you have the option to use rechargeables, but alkaline cells make a reliable and cheap backup. But bear in mind that the battery life is strongly dependent on the backlight level. Handheld sets usually find their position very quickly outdoors, so you won’t need to keep it on all the time if the battery life is important. However, for cockpit use, many can be wired into your boat’s system with a flying lead or cradle.
Charts
If you already have a chart plotter, getting a handheld which uses the same chart cartridge is best. Even better, if the plotter uses the same operating system you won’t need to learn a new one. All UK charts are based on UK cartography and you should ensure they are up to date. Some are still based on 19th century surveys and errors will still exist on the most up to date releases.
Screens
Unless you have a pocket size chart plotter, the bigger the screen the better. The smaller versions have tiny screens which can make constructing a route difficult. The larger handheld sets have screens of around four inches and make a real difference. Screen brightness can vary. Some you can read in sunlight but with others you have to tilt the screen for best results.
Accuracy
The best sets are the ones which support satellite differential GPS – WANS or EGNOS. Basic GPS only offers 95% accuracy – good, but the other 5% inaccuracy may be up to 100m. If a satellite goes down, your GPS will use inaccurate data to plot your position. Satellite differential GPS ensures greater accuracy.
Which one?
Good research before you buy any handheld chart plotter is essential. Chart plotters from Garmin range from £165 to £330 while Raymarine also offer plotters from £180 - £300. Other stockists include Magellan, Geonav, Lowrance and Airo.
Set up
Like a mobile phone, your first instinct is to open the box, insert the batteries and get going! But it is vital to study the manual and get to grips with the complexity of all the functions before you do.