Contents: Offline or online?

Offline or online maps?
Offline maps
Online maps
Silent battery-killers

Offline or online maps?

This is an easy question to answer. An offline map, stored on the GPS device, is essential. With smartphones we’re used to seeing online electronic maps, but to have good maps in the wilds you must take them with you. An online map can’t be relied on.

You should still take a paper map and compass because they are ultra-reliable and will work long after all your batteries have died. If you don’t know how to use them, then read map & compass.

Offline maps

Do use offline maps. Just as you can store photos, music or videos on your phone, you can also store maps.

However, our smartphones don’t normally come supplied with any offline maps and no apps suitable for navigation in wilder terrain either. Phone apps and GPS units both need good topographic maps adding to them before they’re ready for outdoor adventures.

Some GPS units come supplied with pre-installed mapping but check if it’s any good. eg In 2022 Garmin were supplying handhelds and watches to America with pre-installed maps that had contours on them. However units heading for the UK had maps without contours. No good. Fortunately this is easily rectified as third party map-makers produce good Garmin-compatible topo maps for free.

On a phone, a good navigation app will make it easy to download the mapping you need, and make it available in the app. GPS handhelds also make it easy to put maps on them.

Offline mapping will work anywhere on earth, well away from phone signals or internet connections.

Offline maps stored on a phone allow it to be used in flight-mode. This switches off all the 2-way wireless technologies which will significantly extend battery life. You don’t need a phone signal, the internet, WiFi or Bluetooth to navigate perfectly. All the location information your phone’s GNSS receiver needs is obtained from the overhead GNSS satellites.

If navigating with a smartphone always put it in flight-mode to save battery.

Online maps

Avoid, avoid, avoid. If you use a phone with an online map then you need the internet. If the phone signal is poor or non-existent you will lose your mapping.

I can’t stress the dangers of trying to use apps and maps like Google Maps too much. Even if you download a section for offline use, these maps don’t have contours that show how hilly the ground is and lack any significant detail out of towns. They are a terrible and potentially dangerous choice for outdoor adventures.

In 2021, Google Maps showed dotted lines that looked like routes to the top of some of the most challenging Scotttish mountains. They weren’t routes at all and often went through extremely dangerous terrain. Inexperienced walkers were trying to follow these ‘routes’. The BBC reported the story here.

Only use purpose-built navigation apps with good offline topographic mapping.

Silent battery-killers

Away from a WiFi connection you can’t use online maps without a phone signal. It’s the cellphone connection that provides the internet, which provides the mapping. Downloading mapping on-the-fly flattens the battery unnecessarily. It isn’t the only battery-draining process.

When a phone is moved into a weaker signal area it works harder to maintain a cellphone connection by turning up the power on it’s transmitter. If there’s no signal at all, it never stops trying, at maximum power. The phone’s battery will die much earlier.

“The worse the signal, the more power your smart phone will use in trying to maintain a steady reception. If there’s no reception at all, your cellular phone will continue to search for a signal periodically, which can have a drastic effect on your phone’s battery life.”
signalbooster.com

Don’t use online mapping.