http://www.deepbluedive.sageweb.co.u...gue/pr1044.htm
I`ve got a greenforce 100w HID video light withe a spotter lense, at 10m you wouldn`t know it was on and all the numptys with their candles laugh as it cost £700 new.
But go a bit deeper in poor vis and the people of the nearest town get up for work `cos they think it`s morning. Awesome but massive head, I belt mount the battery(which holds the long hose down) but like they say it`s horses for courses, I wouldn`t recommend it because it doesn`t suit everyone. But if you want a light that is suitable for a group of 10 on a night dive then this is the one for you. Umbilical tucks into the harness when not used with a home made goodman(style) handle.
Burn time apparently 90 mins but not to be switched on and off rapidly being HID and dont leave it connected to battery in your bag it`ll burn the house down.
Divers warehouse have them.