Tom
I asumed the computer was getting charged up as I shone the torch on it a bit during the dive, maybe not enough, I'm assuming you mean the little torch, not my main one, was a bit bright last night
and not the conditions or me!
Head mounted, hmm, been blinded by Digger so dont think I'd go for head mount, probably OK in a cave but not sure about open water.
I'll have a go under the bed clothes later
Matt