George and I decided to go electronic when it came to route navigation. Ordnance Survey recommended Road Angel Adventurer 7 which could be pre-loaded with the OS Landranger 1:50,000 scale Standard series of maps. These contain more information than the standard route maps which come with satnav systems.
It took a bit of getting used to, but George was able to plot his map route on his PC and download the itinerary to the device. En route, we used a laptop to amend routes in the southwest, once we'd realised that the wrong campsite had been identified on the penultimate day!
We bought a bike mount for the weatherproof Road Angel but it fell off and George ended up carrying it in his pocket. The other difficulty was the power supply. Road Angel and TomTom satnavs are powered by USB port. It was impossible to power the Road Angel during the day while the boys were biking, and our cigarette lighter in the car broke, so we couldn't use that for charging either. The satnavs proved to be at their most useful for determining end points.
You can buy USB charger adaptors, but we were reliant on power hookups overnight to charge the satnavs. And thanks to Mr Hopkins at Powderham Castle who charged the Road Angel for the leg to Embla.
Another issue was restrictions on camping for all male or all female parties. Virtually every campsite at which we stopped would only accept mixed parties, and had reservations about the age of the boys. Which means that if they had tried this venture on their own, they would have had difficulty finding overnight stopovers. Bodmin Camping and Caravan campsite wouldn't accept the party full stop, because there were an inadequate number of adults for the number of minors - irrespective of the purpose of the ride.