With a compass and barometer, this rubber cased, reinforced GPS receiver is the one thing you want with you in an outdoors emergency. This and a helicopter. They're the two things you want. And a gun. Waterproof to one metre, it can effortlessly survive dunks and has no fear of being dropped, or trampled by wild boar. Compatibility with National Geographic Topo maps means you can plan and navigate walking routes and it also includes a 2-megapixel camera, flashlight and voice recorder perfect for filming your own version of Blair Witch Project. However, despite finding locations quickly, the Triton 2000 is tricky to use, has an unresponsive touchscreen that's hard to see in sunlight, and doesn't appear to work in cities.