Believe it or not, my watch was the one item which consistently helped me throughout my travels. A good quality backpack is great, strong walking boots are imperative, however, I found my tactical watch indispensable when trekking around south east Asia. Many nights of my travels were spent in a tent with little in the way of modern technology. My phone regularly ran out of battery for days on end and I had little contact with the technological word with which I had come accustomed.
This is where my watch came in. After consulting a military watch review website I purchased the Suunto Core watch due to its range of features and weather predicting technology. The advanced barometer proved essential for warning me about oncoming tropical storms, allowing me to set up camp an hour or two in advance (getting stuck in a tropical storm can be disastrous). The compass and stopwatch helped me navigate (using a map) when my phone was out of battery. The solar powered battery never ran out on me either!
I must recommend purchasing a military/tactical grade watch for trekking and travelling. When all other technology begins in fail as you move into more natural environments, your watch will stay running to guide you through your journey.