| I have no idea why you should have 2 back up light during your fundies.
During cave you need 2 each. Basic rule is three light sources per person, but the sun is also included in that.
This ruled is based on old statistics with failure rates for lights.
I don't have my cave manual with me but with 3 lights it was something like a 0.1% change of no light during 1000 dives which is considered acceptable.
With my 2 led back up lights I consider that change smaller, but that's fine with me.
Anyway, as far as I'm aware you should have 1 during fundies, although 2 years ago I had none and that was fine with Andy.
Roel |