One of the essential pieces of equipment that a Technical diver, or any diver should have and be familiar with using is a light. If you are interested in diving in an overhead environment then the diving torch becomes an essential piece of equipment. In fact if you are diving overhead then you need to have 2. Or if leaving the natural light zone, you will need 3. Ideally your primary light should be very bright with a good burn time. There should also be a way to clip it off when not using it.
A few companies offer some that come with special handles that wrap around your hand. This leaves your hand open and allows you to use both hands freely. Ideally the your primary light offers at least 300 lumens and has a battery life of 8 hours or more. You don’t use it for 8 hours but it is good to use it for half it’s life before changing batteries or recharging. Then for back up lights you want to have them small enough to fit in your pockets or on the side of your harness. These should be clipped on and tucked away under bands to prevent it from dangling and becoming an entanglement hazard. Diving torches don’t need huge amounts of looking after. Mainly just a good rinse in fresh water after every use and a little silicon lubricant on the o rings after changing batteries.