by bobby49 » Aug 19, 2019 6:44 pm
There is no hard list of requirements. Each caver puts a different priority on flashlight features.
In no particular order, I would list these:
1. Waterproof
2. Highly reliable
3. Lightweight
4. It must operate on a relatively common battery, preferably rechargeable such as a type 18650, with no dangling wires
In addition, I prefer a headlamp style light that can be easily mounted on the front of my helmet. I prefer a flood beam, not a spot beam. I prefer a light with selectable intensity levels. I prefer a light with very high efficiency. I prefer a mostly-metal headlamp with the switch on the right side, since I am righthanded.
As a result, I use a Zebralights headlamp. I normally carry one or more spare batteries in my cave suit, and a complete spare headlamp in my cave pack.
Some people complain that it is too easy to accidentally hit the switch and turn it on. Easy remedy: back off the end cap so that the battery cannot fully engage. Then twist it tight when you want.