Getting lost while driving is a thing of the past thanks to the miracle of satellite navigation. Many cars have built-in sat navs, but millions still don't. These days you can pick up a very basic sat nav for under £100, but with free or cheap smartphone apps to guide you, why bother with a dedicated GPS device? Here we explain which are the best satnavs you can buy in the UK in 2017.

Do you need a satnav?

With satnav being part of virtually every smartphone on sale today, you'd be forgiven for wondering why anyone would buy a dedicated device.

But, before you go down the smartphone route, standalone satnavs still have several advantages. First, they're dedicated. It might sound obvious, but think about it: it does one job. No distractions such as phone calls, texts or notifications and no power worries. 

Dedicated devices tend to have more options and features, and most have a matte screen that isn't reflective like a smartphone. Plus, you can lend a satnav to someone. You can't if it's also your phone.

Another advantage of satnavs concerns map data. With a smartphone app, either the maps are stored locally at the expense of a chunk of your phone’s storage, or they’re downloaded on the fly which means using up your monthly data.

With a dedicated unit, all your maps are stored locally in memory that you don't need to free up for other purposes. Plus, if you're driving in an area with poor mobile coverage, you might find yourself stranded with no map at all, while a dedicated sat nav always has its map data.

That said, smartphones can be great satnavs and some will still prefer them. You'll need to buy a mount for your car, though (see our favourites by clicking here). You'll also want a USB adaptor that plugs into your car (if it doesn't already have a USB port built in).

You'll also want a USB adaptor that plugs into your car (if it doesn't already have a USB port built in). You can use the smartphone's battery, but using the GPS reciever and screen for a few hours contiuously can easily drain a fully charged phone.

What to look for when buying a satnav

It isn't enough for a satnav to tick all the boxes for the features you're after. It's how they work in practice that counts. For example, any satnav worth its salt will have a points of interest database which includes car parks, petrol stations, hotels, cafes, cash points and more.

But is the information any good? Can the satnav intelligently list potential points of interest based on your route, or does it merely list them based on distance as the crow flies?

And as well as speed warnings, another feature that will make your journey easier is lane guidance, so you don't accidentally leave the motorway at the wrong junction. Some satnavs even go as far as to show you a photo-realistic view of the junction to help you know where to turn.

Free map updates are worth seeking out when buying a new standalone satnav, as paid-for map updates can be almost as much as buying a new satnav in some cases.

Finally, if you're buying a standalone satnav or paying for an app, make sure you get the maps you need. If you drive to Europe, it's worth spending the extra £30 or so on maps of Western Europe as adding individual country maps can be costly.

Now, here are our four favourite dedicated sat nav units currently on sale in the UK.

Also see: Best Gadget Deals

Garmin nuvi 57LM

Garmin nuvi 57LM

This 5in sat nav is one of the best selling on Amazon, and with good reason. For a dedicated device it has every essential function for a budget price.

For the price you get preloaded maps of the UK and Ireland, and Garmin promises free lifetime map updates for the inevitable route and road changes. The nuvi has one of the clearest audio and visual combinations on the market, with features like Lane Assist and Junction View helping to make the sat nav experience as stress-free as possible.

A great addition is the polished Up Ahead feature, which lets you know about places of interest en route to your destination, from restaurants ro cash points and petrol stations. 

TomTom Start 25

TomTom Start 25

Much like the Garmin nuvi 57LM, this well-priced 5in sat nav from popular and trusted brand TomTom comes with lifetime map updates. It also ships with Western Europe, not just UK and Ireland.

It has high-end features despite being available for under £100, including speed camera location warnings in real time and parking assist, which can navigate you directly to the best place to park (it won't park for you though, unlucky).

It's easily attached to the dash or windscreen with an integrated mount. The screen cleverly flips to support whichever way round you want to use it. 

TomTom GO 5100

TomTom GO 5100

The TomTom GO 5100 is a premium 5in sat nav device. Its high price reflects the fact it has global coverage - you can take it anywhere on the planet and it will give you up to date routes and advice.

It works by shipping with an integrated SIM card with unlimited data - meaning you never have to worry about running out of data, just make sure you can plug it in in the car to keep it charged. 

It has excellent traffic information, and the system smartly reroutes you based on minute by minute traffic changes. It also integrates with the TomTom MyDrive app, allowing you to plan routes in advance on your smartphone or tablet.

Garmin nuvi 2699LMT-D

Garmin nuvi 2699LMT-D

This is a good, if pricey, option if you want a larger 6in screen sat nav. It has all the features you'd expect from a modern GPS system, with added clever functions like Bluetooth for hands-free calling integration and the ability to function outside of cellular service.

It also has voice-activated navigation options to minimise the time needed to take your hands off the wheel to use the touchscreen. It also has clever integration with Garmin's Smartphone Link app, allowing you to record detals of your travels such as where you parked, plus send addresses or locations straight from your phone to the sat nav.

It does only come with UK and Ireland maps for the price though, so you'll have to buy other map packs if you want to use it abroad.